Product: Credit card or prepaid card

Have a few open credit cards under this bank. I have been working diligently to pay off more than the minimum amounts on these cards every month to pay them off. Two cards under same bank were paid off recently but one of them had higher interest rate and fees monthly, therefore started making as big of monthly payments as I could afford to get this card down and hopefully reduce the monthly interest fee. However, a couple instances where the monthly interest had gone up even though I was paying a higher amount that month? I also have called to speak with the bank/company numerous times since I have been a card holder for awhile now with on time payments ( except once when we moved and I did not receive their statement on time because they mailed it to old address. I informed them of this and they stated it would not be an issue since I explained and they a manager said it would not be an issue ... then a year later it showed up on my credit report and to this day I can still not get them to assist me with changing it as they initially stated. ) This bank/company seem to make a lot of promises that they do not keep to consumers obviously! My issue now is on this one particular credit card with higher monthly interest ... as I paid every month well over the minimum amount to pay off finally about three weeks before their due date in XX/XX/XXXX, as I was paying payments on this card two or three times in the month just to get it paid off as well. Well I logged on as I usually do to pay my credit cards online through their website directly, and again mind you, I had already paid off two other, same bank though, credit cards in the previous months without any issue of this happening but when I logged on to this site, the balance stated what was the statement balance as well as pay off balance was and I paid it in full, again three weeks before the due date of XX/XX/XXXX. When later asking the representative of this, their response was that I should have called in for a balance pay off? This was not a mortgage or car payment and I had never had to do this for any other credit card or the credit cards I held with them that were already paid off now? The issue is that by XX/XX/XXXX, I received an email stating new balance owed? This is almost four weeks after I paid it off, long before their due date? I was charged an interest/purchase fee of {$25.00} due for XX/XX/XXXX. I called and spoke with them and they refused to credit me and my account, stating one, I should have called in? I never have done that with any credit cards ... as they all state what is due at that time? I have also never been charged an interest or purchase fee by anyone AFTER I have already paid off the entire card as I already did. Please look into my monthly account and you will see I paid two to three times in a month to get rid of this balance because of the high interest and then they still hit me with it ... with a large {$25.00} fee AFTER there is nothing on there and I have not even used the card in at least a year? I had not planned on using this card either since I knew the interest on this one card was higher but still after speaking to a manager there and they said ok we will reverse it because I stated it seemed like fraud because they gave some XXXX  about paying two consecutive payments before to avoid interest rate charges? Well one I did do that, two I had spoke to previous reps who never mentioned that, and three, I never had this with their other two cards or any other credit cards I hold? They do seem to be handling this fraudulently or at best underhanded and unethical practices!! I would close my account out completely, however, due to it affecting my credit negatively, I can not take that route at this time otherwise I really am very skeptical anyway to use any other their cards. My family also have credit cards through them but once they are all paid off, I think we will close out with them completely and find a new bank/company to deal with. I will never use their one card ever again that I am filing this complaint on but it is not just the card..it is the company and how they handle issues that arise with their card holders and whereby they say they will help you and fix an issue but then not!! This manager stated the {$25.00} would come off completely and they would waive the next month ( XX/XX/XXXX ) fee as well since the way the billing month fell, they stated I would pay again!!???? This is crazy and totally unethical practice ... they are stealing money by interest fees! WRONG and not fair! Especially because they offered to fix it but have not, it has been over a week since they promised to fix this and called today and was told it might take longer but they could not fix it themselves? Well I can see where this is going ... my payment date is AXX/XX/XXXX, and they would like for nothing more than me to NOT pay this so they can charge more and now my payment will be late!! Please investigate this so no one else goes through this as I know I will be stuck paying these crooks but it is wrong and my wife complained to them as well because she pays the bills online for mine and her account but they did not care who they spoke to recently, they were going to pretend to take care of it but not offer a solution. Also, they no longer offer any online assistance like they use too ... NO email address to submit ... NO online direct chat as they use to offer it but has not been there as long as the email ... about three months now ... no extra help what so ever! What gives these companies the right to rip you off when you are paying them on time and more than the minimum amount every month!! Just sickening and I am done with this company! Please investigate my situation as well as anyone else with a similar complaint! Also, the ending account number has been changed recently since while online was trying to access assistance but it requested a new card instead and tried to cancel it but it went through I guess ... so should be ending XX/XX/XXXXbut now says ending XX/XX/XXXX ... same account but will send back new card because I do not want a new card or anything from them after all this!! If not enough evidence/information for you, please request more and explain what exactly you need and I will provide it, they do not make it easy to pull up and print ... only able to see on my end ... once printing not so easy to see for accessibility?