Product: Credit card

XX/XX/XXXX, after looking at my statement I noticed that my credit card company Citi/Shell had reversed XXXX payments made XX/XX/XXXX, XX/XX/XXXX and applied late fees to each of these payments. I was not notified by the credit card company of any of this and only found out by signing into my online account. At this time, I contacted Citi/Shell customer service and told these payments were reversed because my bank had returned them unauthorized. First of all, if my bank had returned them they would have notified me ( as well as a bank charge for a returned item ), of which my bank had not. Secondly, why were they just not stating these unauthorized payments 3 months later? I asked these questions to the creditor and I was not given an explanation. I was just told they were unauthorized by my bank and I needed to contact my bank, which I did and my bank stated that they had no record of any unauthorized or returned payments from this creditor. I showed this information via a letter from my bank to the creditor, as they requested and disputed these reversals. Every time I submitted additional proof to the creditor, they would come up with other documents or reasons for the reversal. After submitting two letters from my bank, they now are stating that, the account number was transposed wrong in their system. These payments were made online as they had been previously and for over 3 years the same way. The online payment system does not require you to type in the account numbers each time you make a payment. You use a drop down menu to pick the account in which you would like to pay from. This was set up when you set up the initial online account and unless you go in and change the bank information, which I had not, the account number remains the same and you just choose which bank institution you would like the payment to come from. These payments were made in the same fashion as they had been for well over 2 years, if not more. The numbers could not have been transposed wrong. Each time I explained this information to Citi they refused to listen to me or came up with a different reason for the reversal of the payments. This was not an error on my part, but I was penalized with late fees and additional interest for these payment of which I had disputed. These late fees and interest reached over {$500.00}. I made payments on the account during the dispute for the balance that I owed, minus the disputed payments. But, since they had the minimum over {$200.00} from the reversed payments, I never knew what the true minimum was without the disputed balance. They offered no assistance on that either. The late fees were applied each and every month, even after $ XXXX payments were made. On a normal billing cycle prior to the reversal of the payments, the minimum due was {$25.00}. So, I paid {$50.00} to ensure the true minimum was made. This issue was never resolved due to Citi refusing to correct the issue or explain to me why they reversed the payments 3 months after they were made. They never acknowledged an error in their system and never adjusted the billing during the dispute. The fees and interest continued to accrue to make the minimum balance a ridiculous amount, because of all the fees stemming from this error. Please help me, this has been put on my credit report and the balance they show as owed is late fees and interest in excess of {$500.00}. Let me know what documentation you need and I can and will produce it.