I have an ATT Universal credit card with Citibank. On XXXX/XXXX/15, I wanted to authorize an online transaction in the amount of XXXX British pounds ( a bit more than {$3000.00} ), to a firm in the XXXX XXXX, for the purchase of a collectible item ( a coin ). Citibank 's fraud protection unit often blocks transactions of this type ( they blocked XXXX of mine just three weeks prior ), and I contacted Citibank through its online secure messaging system to notify them that the transaction would be coming and that it was valid. The electronic response I received told me to telephone them, which I did on XXXX. I gave them all the information for the transaction, including the anticipated date it would be completed ( XXXX/XXXX/15 ), and I was assured it would be processed. 

On XXXX, I received notification from the vendor that the transaction had been declined ; I also received an email notice from Citibank that it had been declined. I telephoned Citibank again in the evening of XXXX, and they advised that the account had not actually been noted to approve the transaction ( despite the separate electronic and telephone notifications I provided ), but that they would do so now : I was assured that the transaction would be approved when the vendor resubmitted it the next day, XXXX ( at this time it was already after business hours in the XXXX XXXX ). As further assurance, the Customer Service Representative told me that she or someone else from Citibank would contact me when the transaction went through. 

After speaking to Citibank, I contacted the vendor to authorize him to proceed. 
On XXXX, the vendor notified me that the transaction had again been declined ; I also received an e-mail notification from Citibank that it had been declined, with a request that I contact them to verify whether it was valid. 

I AGAIN verified that the transaction was valid, using Citibank 's electronic verification system, which advised me to have the vendor re-transmit the transaction. I then attempted to have the transaction go forward ... and it was declined again. 

I then XXXX telephoned Citibank, but I was not able to reach anyone at Citibank to clear this up -- both times the phone system just went through voice prompt XXXX -- but when I checked my account online I found that they were XXXX " pending '' transactions for the vendor, each in the full amount. Those XXXX " pending '' items match up with the XXXX separate attempted charges -- each of which was returned as " declined. '' Notwithstanding that the charges were all declined, my available credit limit has been reduced by an amount equal to the total of the XXXX failed/declined transactions. 

I then threw up my hands and ran the transaction using a XXXX credit card -- which went through without a hitch. 
