Product: Credit card

Citi XXXX XXXX AAdvantage closed my account on XXXX XXXX, XXXX ( of course given this was XXXX, no one at Citi could explain what was going on that day ) after 15 years of being a customer with no prior notice nor attempt to contact me via phone or email. No payments were due at the time as I had already paid {$6500.00} in cash ( direct debit ) + a {$270.00} credit from a vendor in that month of XXXX ( my credit line was just north of {$16000.00} ). 
Citi claims that on XXXX XXXX, I made ( another ) online payment of {$2500.00} ( from a different account than the other {$6500.00} ) that was returned NSF despite the fact that my account at XXXX XXXX has no record of anything being presented at that date ( or for the entire month of XXXX ) and in fact sent a Letter to Citi explaining this. I was never notified by either institution of any NSF until Citi closed the account on XXXX. 
The root cause of this either an outright mistake or the Citi Website 's poor design which is misleading and prone to error given the nature of how customers select accounts in a Drop Down box to choose which account the direct debit is made from. I have XXXX accounts linked to this Citi account and one could easily choose the wrong account. Given the fact that 2 weeks had passed since this payment was, evidently, initiated I of course could not remember exactly what transpired. But I believe I tried to cancel this transaction realizing that the wrong account had been selected. Citi had a record of the transaction being cancelled in fact but can not tell if " I '' did it or if Citi did after the fact. It is now not even clear to me IF there is a Any Way to cancel a transaction which is of course poor design at best and not my fault. 
I did contact the bank and despite a helpful customer service rep named XXXX in Kentucky, after weeks of going back and forth with No Explanation of the " cancelled transaction '' that Citi said I had XXXX NSF transactions over the life of the account ( the prior one being on XXXX/XXXX/XXXX - almost enough time even for a bankruptcy to be expunged ) and there was " nothing they could do '' and that the account was automatically terminated. 
Furthermore on XXXX XXXX, I received this notice from Citi saying they had forgotten to notify me that they had charged the Annual Fee to the card of {$450.00} : We charged you an annual membership fee without prior notice We discovered that we failed to include a statement message on your Citi ( R ) / AAdvantage ( R ) XXXX XXXX ( R ) account notifying you of the annual membership fee the month before we billed it. We apologize for our oversight. 
Lastly I paid the entire balance on the account to {$0.00} on XXXX XXXX ( as I said I would ) and there is currently a {$24.00} credit due me on their website for which they have not contacted me nor paid me. 
Furthermore on XXXX XXXX, Citi sent me a lette To the extent that there is No Capability to cancel an initiated Debit on the Citi website nor any notice being given of a problem or potential problem, that is not a proper website for a very large financial institution to be using to the detriment of their customers. 
Of course my credit has been impaired by Citi 's unilateral actions and with No Opportunity for me to rectify the situation. 
I would appreciate the CFPB 's help in getting this account re-opened and the appropriate fees reimbursed. 
Perhaps more importantly would be delineating some Standards and Procedures around Web Design / UI and clear method for Consumers to be able to cancel transactions when mistakes are made and that Consumers be contacted before account closure to be given the opportunity to ameliorate and mistake made due to poor Web Design until such time as the Website can be improved to address this issue. I 'm in the XXXX business and I know there is a proper way to do these things - Citi is not doing them