NatWest and RBS Cyber Monday computer meltdown EMPTIES customers' bank accounts Some customers find hundreds of pounds missing from their accounts NatWest says small number affected - but cannot confirm how many Customers with no money left in account are fearful about bills coming out Glitch also left millions unable to pay for online purchases or in shops British troops in Falklands couldn't pay for dinner after cards were rejected Groups of shoppers turned away en masse at supermarkets yesterday NatWest had similar problems last year, with wages 'disappearing' Fiasco in 2012 cost the bank £175million in compensation claims By Mark Duell, Sean Poulter and Richard Marsden NatWest customers woke up this morning to find they had negative amounts in their accounts after their money was emptied by a computer glitch. Supermarket trolleys full of food were abandoned, mothers were unable to buy milk for babies and motorists could not purchase fuel as the error also left Britain's shoppers high and dry. On the biggest online shopping day of the year, customers of the Royal Bank of Scotland (RBS) Group, which includes NatWest and Ulster Bank, were left unable to use their debit or credit cards. A computer gremlin at NatWest has left the bank's customers unable to use their cards or make online purchases today The problem - which lasted for around three hours between 6.30pm and 9.30pm yesterday - also affected use of the bank's cash machines, smartphone apps and websites, on 'Cyber Monday'. Other customers logged on to find they were overdrawn - when there should have been funds available in their accounts, but the bank said this had only happened to a small number of people. As well as anger among internet users, people complained about being caught up in long queues at supermarkets and petrol stations as those affected struggled to find alternative payment methods. The bank has apologised to customers across the country who were hit by the problem. Reports of cards being declined began at 6.30pm - when many people go online to buy groceries after work. Cash machines have been affected and one customer reported NatWest cards being declined 'en masse' at a supermarket in Kent At 7pm, one customer reported NatWest cards being declined "en masse" at a supermarket in Kent. NatWest customer Natasha Lewis said her card was declined while getting petrol last night, which caused "a huge lot of grief as I knew I had money in there," and she had to call her partner to walk up to pay for it instead. But the 26-year-old nursery nurse from Birmingham experienced further problems this morning, being woken up by a text message that she was overdrawn. Since then she has had to cancel a job interview because she had no money to get there, and was not able to reschedule it. Ms Lewis told MailOnline: "I rang customer services, to be on hold for an hour to be told I took money out which was not in there. I explained I got paid that day and I checked my available balance first like I always do. Then (the woman on the phone) told me that my money had disappeared and there were no signs of money going into my account yesterday. She wanted to take money out of my savings to cover it. "I said "no" as it's not my fault the money has gone, so I shouldn't have to pay. I had a job interview today which I've had to cancel as I've got no access to money to get there as my partner has the car. The bank is a joke. She added that she will be changing banks if the problem is not sorted today, because she has a number of bills to come out tomorrow. Posts on Twitter included: "NatWest useful banking - really? Useless banking is more appropriate. Another person tweeted: 'I'm pleased that Natwest has crashed. No, not that. Furious, that's it.' RBS customer Rachael Horrocks, 24, said: 'Just checked my account now this morning and my account was in minus, when I had reasonable amount of funds in there yesterday. Today they just disappeared. The freight imports co-ordinator, who works in Colnbrook, Berkshire, near London Heathrow Airport, told MailOnline: 'I was ringing RBS for one hour this morning, only to be told that they don't know when they will be able to return services back to normal. Absolutely useless. She said there was around £200 in the affected account when she checked at 4pm yesterday, but found it was showing -£65 when she woke up this morning. Ms Horrocks added: 'I had called again now and they have advised me that people should start seeing their money back in their accounts, but mine still has not been restored.' Customer Jill Gale said she was affected last night and by the outage last year - and has finally had enough of NatWest, so switched banks this morning. The 34-year-old from County Durham told MailOnline: "My wages disappeared last year for three days and last night when I filled up my car I couldn't pay for my petrol. Why should I carry £50 cash in my purse? Surely having my card and ensuring I have valid funds in the account should be enough. As it happens I had a separate Visa which I used. But it is humiliating when it happens, even though the people behind me were in the same position - and two of them didn't have any other way of paying. Needless to say, the first thing I have done this morning is change banks. My new bank will close my old accounts when the switch is successful, but not without a complaint from me first. NatWest apologised for the glitches and told the Twitter community it was trying to resolve the situation A pilot and his crew who arrived yesterday in the Falklands for a two-month tour found once they reached their base that they could not use their cards when they went to a cashpoint to buy dinner. The pilot's mother Sarah Prosser told MailOnline: "They all had to queue up to use a phone to call home to find out what was going on and to tell families that they could not access any money. The system issues that affected our customers last night has now been resolved and the vast majority of customers are experiencing a good service. We have heard from some customers who are experiencing issues this morning as systems get back to a fully normal service. If any customer is still experiencing issues, they should get in touch with our call centres or come into our branches, where our staff will be ready to help. We will continue to monitor the service throughout the day, and apologise for the inconvenience this has caused. Not only are the poor lads away from home for Christmas, but they can't buy anything either. "The least RBS/NatWest could do would be to fly some "Christmas cheer" down to them and sort their accounts out as soon as possible, as a way of saying sorry." And NatWest customer Kim Forsdyke said: "Went to pay in a shop last night and card got declined. Put it in the cash machine and got declined. Went for a meal for my daughter's birthday and card got declined again. This morning, went to log onto internet banking and cannot. Susan Allen, director of customer solutions at RBS Group, told BBC News today: 'We sincerely regret the inconvenience that customers have had. There have been some fairly horrible stories this morning about the inconvenience and distress caused for people out shopping yesterday evening. If anybody is out of pocket, then we have made a commitment that we will make sure that everybody is put back in the right position. 'It's very upsetting when you hear the stories, and I've talked to a number of customers and seen their stories this morning, so I can understand the frustration and anger that people are feeling. A spokesman also told BBC Radio Four's Today programme that it was a "completely unacceptable" outage, adding that for "even one customer not to be able to access their money was unacceptable." Sale denied: Twitter users vented their frustration about the crash The bank has had previous problems with technological glitches in mid-2012, prompting Stephen Hester, the former boss of NatWest owner RBS, to personally apologise for the issues that left the bank in chaos. A mother said she was left without milk for her four-week-old baby after the NatWest glitch. Kady Pike, 25, of Basingstoke, Hampshire, told MailOnline she went to a Tesco store last night to purchase milk for her child Ted, but her card was declined three times. She then went to the cashpoint outside the store only to receive the message that the machine "cannot process request at this time." Ms Pike said: "I have just suffered an acute cardiac arrest bought on by a suspected clot I my lung, so my trips outside of the house are very few and far between. Seeing that my card had been declined; naturally I panicked - a) My newborn baby needs his milk and b) What's happened to my money? She then called NatWest but said the member of staff was unable to help further than putting her through to the customer service team. Upon calling them, she was put on hold for 10 minutes and eventually decided to hang up. Her father later went out to buy the milk. The IT problems led to payments going missing, wages disappearing and holidays and home purchases being disrupted. The bank kept 1,000 branches open late in all major towns and cities to help frustrated customers. One branch in West London closed its doors with only two members of staff outside telling customers that they would not know until the next day when services would be restored. Swathes of NatWest customers took to Twitter at the time to complain they were unable to pay with their debit cards. @doitdoesitdidit said: "I can't pay my suppliers, therefor no stock (discrediting me) ruining my schedule and wasting my time." While ‏@OwenThomasTV said: "NatWest online banking down again. Really? Can't pay my bills. Can't take out money. Mr Hester admitted that NatWest had let down its customers after hundreds of people vented their anger over the issue. The fiasco cost the bank some £175 million in compensation. And in October 2012 the bank had to suspend a mobile phone banking App feature called GetCash, after the service was subject to a spate of "phishing" attacks by fraudsters. The bank also had huge technical problems earlier this year when the mobile Apps used by two million customers to access their accounts from iPhones, Android smartphones and tablets failed. Millions of customers were locked out of their accounts for several hours as a result. If you're fed up with your bank and thinking of switching, there are plenty of incentives to move.This is Money's five of the best current accounts is a regularly updated guide to where the best offers are. Top deals include Halifax's Reward Account promising new customers £100 to switch and £5 per month if they stay in credit. First Direct pays £100 to new customers who switch to its First Account. On top of that, the bank is so confident in its customer service that it will give you a further £100 if you chose to close the account within the first 12 months. Santander's 123 current account, on the other hand, pays interest on in-credit balances - 1 per cent on balances between £1,000 and £2,000, 2 per cent between £2,000 and £3,000 and 3 per cent on balances between £3,000 and £20,000. Nationwide FlexDirect offers to pay 5 per cent interest on balances up to £2,500 for the first year, while its FlexAccount delivers free travel insurance. Amy Andrew One angry customer wrote: "I've moved to Barclays after 10 years of nothing but hassle from NatWest ...... Little Britain must of got the phrase "computer says no" from NatWest." Suresh Mekala spent more than £13 on a train ticket from Gloucester to Bath to do some Christmas shopping. But it was a wasted trip as the 29-year-old ended up having his NatWest card declined at several stores - and could not buy anything. He told MailOnline: "I never keep cash as I use my card to pay for all my transactions. But I had a really bad day - I went to my favourite shops got lots of shopping but my card was declined several times. NatWest is the only bank account I have and no cash. My trip was for nothing. 'I couldn't withdraw money from cash point or check my online banking. I'm really frustrated with the bank. A second said: "So pleased I opened a new account with someone else on Tuesday. NatWest are useless. A third spoke for many, stating: "Hey Natwest, instead of giving your useless bosses at the top of NatWest tower massive bonuses, try employing IT people who actually know what they are doing." Iain Chidgey, from data management company Delphix, told MailOnline today: "Software glitches are becoming more and more frequent in the banking industry. Often the cause is insufficient testing. The databases in financial institutions are large and often more complex than in other companies. IT departments provide copies of databases for testing, but by the time a copy is available, the data itself is often old. In our data-intensive world, data can be obsolete after only a couple of hours, but when refreshing just a single testing data set can takes days, the data will never be up to date enough for risk free testing. And, following the technical problems, security specialist firm Check Point today warned customers to watch out for phishing emails which appear to have been sent by their bank. The company's UK managing director Keith Bird said: "Bank customers need to be very careful not to click on links in emails which appear to come from RBS, NatWest or Ulster Bank advising them about changes to account security, no matter how authentic the email seems to be. The first thing I have done this morning is change banks. My new bank will close my old accounts when the switch is successful, but not without a complaint from me first Jill Gale, NatWest customer Attackers have jumped at this opportunity to try and trick customers affected by yesterday's technical problems into revealing their bank details. 'For those attackers, it's just a numbers game, but it could have serious consequences for customers. Phishing emails continue to be the most common source for social engineering attacks. RBS, which is 80 per cent owned by the taxpayer after being rescued during the financial crisis, has also been under fire over the last week over allegations that it drove distressed firms to collapse to buy back their assets at rock-bottom prices. Have you been a victim of the NatWest glitch? If so, please email: mark.duell@dailymail.co.uk NatWest's slogan is 'helpful banking', but that phrase will leave a bitter taste in the mouth for many of its customers, with the bank suffering a spate of major IT glitches recently. In mid-2012 the technical meltdowns were so severe that Stephen Hester, the former boss of NatWest owner RBS, personally apologised for the issues. The bank kept 1,000 branches open late for one day in all major towns and cities to help frustrated customers.