Product: Credit card or prepaid card

On XX/XX/XXXX, I made a purchase of {$15.00}. I paid for this amount on XX/XX/XXXX online through XXXX and have been using this method to pay off my bill since I started using XXXX credit card. When I received the statement in the following month ( XXXX ) for {$15.00}, I disregarded it as my XXXX statement showed that I had completed the payment for that amount.in XXXX, I received a statement with late fees and I called customer service on XX/XX/XXXX to get the matter resolved. The representative who helped me informed me that he filed a dispute for me and that the late fees and interests will be suspended during the investigation. He told me that I would need to wait to receive mail from the dispute department which would take approximately 5 to 7 business days. I called back on XX/XX/XXXX to check on the status of the dispute letter and was told that it should arrive soon. On XX/XX/XXXX I had to call back because I received a XXXX statement with additional charges on the late fees and the representative told me that the fees will be returned after the investigation. When I received the letter from the dispute department, I contacted XXXX for the information that they needed for the dispute and the XXXX representative told me that I only needed to provide my statement with the payment number to indicate that I have paid. I immediately sent this information online and by mail. Since I submitted the information, nobody reached out to me to inform me whether the dispute was accepted or rejected. While I was waiting to hear back, I kept receiving statement after statement with additional late fees and interest charges. I would reach out to customer service each time and nobody was able to provide an answer. I called XXXX and the representative was able to research my account to find that there was a payment of {$15.00} on XX/XX/XXXX payable to XXXX CARD but the payment had not been processed by the payee. I made a copy of this mail and sent it to the dispute department with a letter attached asking whether XXXX XXXX would like XXXX to resend a check or that I make the payment of {$15.00}. No one answered me and sent me a letter to call them. I called and spoke to a representative named XXXX who said that I have to pay for all of the charges and was very demeaning to me. I asked if she can waive the late charges and interests because they were supposed to be suspended the investigation. She kept asking how I wanted to pay today/if I wanted to pay today but nothing regarding helping me look into the investigation. Those were the only two questions that she asked me repeatedly. After the call, I paid the {$15.00} online just to pay the amount that was not processed by the payee. I had to constantly call XXXX XXXX regarding the dispute status and they kept that they never received the proof or that I did not pay. This went on for four months with me calling customer service and sending mail, so I decided to contact XXXX XXXX on XXXX on XX/XX/XXXX. A representative called me via XXXX on XX/XX/XXXX and I provided to him the letter once again. Each time I talk to a representative they always tell me that they do not see the payment. I called XXXX again and talked to a manager who provided me another letter that shows my payment that I can use as proof for the dispute. After sending this final letter over on XXXX, the representative stated that it was sent to the wrong address in XXXX, NC instead of their location in XXXX XXXX, TX. I had been using XXXX to pay for the XXXX credit card and never had this problem until the XXXX payment even though they claimed they have not relocated. After speaking more with the representative on XXXX, I was willing to pay the first late fee as it was sent to the wrong address but requested to waive the fees during investigation. He proceeded to say that they will not be able to waive the fees since the dispute was not found in my favor. I requested for them to close my account because the late fees were supposed to be suspended this entire time. I closed the account because I did not want the fees to accumulate anymore than it already had. 
XXXX reaches out to me after to say : When filing a dispute the fees are held until our Disputes team s completed their research. In your case, the fees were added because we were unable to locate the payment. Unfortunately we are unable to advise why this is the first time the payment was not received from your banking institution. I can assure you that since the XXXX XXXX account has been with XXXX Bank the payment address has not changed. The address in North Carolina may have previously forwarded the payments to us until now. You have since closed your account, we are unable to remove any fees from your account. Thank you for allowing me to address your concerns again. 

I believe that I shouldnt have to pay for the accumulation of these late fees when I was told since the first time I spoke with someone regarding the matter that the fees would be suspended the whole time. Since I closed my account, they were not able to remove the fees but were still able to continuously charge me until this very day. No one took the time to explain the charges to me until after I have closed my account. 

The main concerns of this problem are summed up in 3 points : 1. Why did I get charged late fees and interest during the investigation and dragged out the time to solve the problem by physically sending mail back and forth when we can easily solve it online?

2. Why did no one ever tell me the status of the dispute case?

3. Why cant they remove any fees from my closed account, but can keep adding more fees and interest?