He said he was from Microsoft. Then he tricked me out of £121 "He asked me for my bank details and - this is where I'm so annoyed with myself - I gave my credit card details, which I should never have done," Peter said. The man then said he would take remote access of the computer to install the software and suddenly "reams of numbers were covering the screen and the cursor was moving all over the place." Peter then looked at his printer and saw an email printout the conman had sent from Peter's email account confirming the £121 payment for a year's cover, even though he had not revealed his email address or password. Peter contacted his bank, HSBC, immediately, but the money had already left his account. As he had authorised the payment, Peter was told the money would not be refunded. The Telegraph intervened and HSBC has since paid a full refund "as a gesture of goodwill." At HSBC we take fraud very seriously, and use market-leading detection systems in our efforts to prevent it. However fraudsters also target customers directly and we recommend customers are vigilant at all times and only enter into a transaction and divulge their card information when they are confident with what they are purchasing and from whom," said an HSBC spokeswoman. Peter has now had his bank cards and bank passwords changed, as well as his computer security details. "It was really quite a traumatic experience and I feel so guilty for being such a fool," he said. At 86, I should know better. Consumer watchdog Which? is warning computer users, and particularly elderly ones, to be on their guard for such scams. Figures from Microsoft show that one in five people in Britain has received a similar call since the scam emerged in 2010. A survey conducted in January this year found that half of the victims of the scam were over the age of 55, and the average amount lost was a painful £745. Richard Lloyd, the executive director of Which?, said technical support scams were criminal and could be "hugely distressing." "Our investigation into the Microsoft scam revealed they can put people at risk of ID theft or fraud and leave victims seriously out of pocket," he said. Which? said the scam was also affecting the elderly's trust in technology. Microsoft's chief security adviser, Stuart Aston, said: "In essence, this scam is a confidence trick by often quite sophisticated criminals, who are adept at gaining their victims' trust by using a name like Microsoft, adopting industry jargon to make them sound professional and using apparently personal information to appear legitimate." Microsoft insists it will never call customers "out of the blue." Mr Lloyd said: "Be vigilant to the threat from scammers and protect yourself by never giving an unsolicited caller remote access to your computer. If you think you've been scammed in this way you should run a virus scan, alert your bank and contact Action Fraud to report it. Essential steps to protect yourself from scam calls Always be suspicious of unsolicited calls or emails offering help with a security problem, or any other computer problem. Microsoft never calls in this way or asks for money for fixing a problem. Do not go to a website, install software or follow any other instruction from someone who cold-calls. Take the caller's details and pass them to your local authority. If you have received a call and think you may have been a victim of a phone scam already: Change the passwords to your computer, email and any financial accounts, especially bank and credit cards. Scan your computer to see if rogue software has been installed. Contact your bank and credit card companies if you think your details may be at risk. Ask them to freeze the account and issue a new card. If you have lost money to card fraud or paid for bogus PC support, contact Action Fraud and get a crime reference number. This will help pursue a claim with your bank for lost funds. See actionfraud.police.uk or call 0300 123 2040. Read more at microsoft.com/security.