Product: Credit card or prepaid card

I opened an account with Synchrony Bank/MasterCard ( TJX Rewards ) on XX/XX/XXXX. Throughout, I have been a loyal customer and frequently patronized several of the TJX Companies using this card. At a later point I attempted to add my wife as an authorized user, however the cards kept getting lost in the mail. Each time I reported that I wasn't receiving the new card the bank would close the account ( potentially harming my credit score ). This occurred three times before I finally received my second card. 
Fast forward, ( weekend of XX/XX/XXXX ) my wife and I were attending and out-of-town event in which the vendors did not accept cash, so we relied heavily on this card to plan our purchases. After arriving at the event we learned our card was no longer working. We reached out to Synchrony customer service since we had not received any notices or emails explaining that the card was frozen. At that point we were told that the account was permanently closed due to a payment being rejected. The reason for the payment rejection was due to the fact that we had double paid Synchrony in an attempt to pay off the balance in full. We attempted a full account payment of {$2600.00} on XX/XX/XXXX ( two weeks prior to any amount coming due on our account ) for the purpose of freeing up our credit limit as we needed to make a timely and expensive online purchase with the card. After waiting several days and not receiving any notice from Synchrony that a payment was received and there being no record of the payment posting while viewing our online account page, we made a second attempt to pay off the balance of {$2700.00} on XX/XX/XXXX. This second attempt ended up going through immediately after the first attempt and we believe there wasn't enough funds to cover a double payment in that amount. ( Unfortunately our bank XXXX XXXX XXXX was having issues and not accessible during this time so we could not check those account balances for available funds ). There was certainly enough to cover the full balance though if we had not double paid. Again, at that time no money was due. We were just trying to zero out the balance. It should also be noted that from the time the second payment was rejected ( on XX/XX/XXXX ) up until we received an official email notice ( on XX/XX/XXXX ) numerous expenses had accrued on the account that are still due. 
After calling in, we were told the account was closed and basically it was implied they had no interest in doing business with us. We spoke to account managers, XXXX ( ID # XXXX ) and XXXX ( ID # XXXX ). I asked why they would close an account over an accidental double payment - when no money was even due ( assuming that these simple errors would be preferable to things such as missed payments or late payments ). XXXX said there must be a pattern of " insufficient funds '' transfers on our account- which is not true - and he could not provide dates or evidence of such. We requested several times to speak to their supervisor, XXXX. Their response was rude and evasive and we have still not received a call from XXXX to discuss our issue. 
Thus far, Synchrony Bank has done everything in its power to harm my credit score and records and at the same time discredit their name and reputation along with their partners, XXXX and TJX Companies. They've shown no interest in growing or retaining a customer base. Synchrony share holders and partners should be gravely concerned.