Product: Credit card

I made a {$600.00} payment earlier in the month of XX/XX/XXXX so when it came time for my payment to be due of {$35.00} on the XX/XX/XXXX the system said there was no minimum payment due and yet there was an automatic payment scheduled. I accessed the account and cancelled the automatic payment since there was nothing due. Then I started receiving notices from Synchrony bank on my XXXX store card that the automatic payment and the manual payment that I made was returned for insufficient funds and that they closed my account to future purchases due to the XXXX returned payments. I also was charged a late fee for not making the minimum payment due even though I had already made a payment earlier in the month and the system told me that there was no payment due. I called synchrony to get the issue resolved and tried to explain that I cancelled the automatic payment and did not schedule a manual payment in addition to the automatic payment because there was no minimum payment due. They just keep repeating to me that I did not cancel the automatic payment but in fact scheduled a manual payment. I kept telling them that there has to be a technical issue because I did cancel the payment since I already made a large payment that covered the minimum payment and when I accessed the account it told me that there was no minimum payment due. They did in fact refund the late fee but refuse to re-open my account because their system has never screwed up or had technical issues before. The only way they will re-open my account is if I get a letter from the bank stating that the bank returned the payments in error which they did not because I cancelled the automatic payment and did not schedule a manual payment so I expected no payments to come out of the account. I did not expect double the payment to come out so I did not put the money in the bank to cover XXXX payments of {$100.00} each to come out of the account on the same day. The only other way to re-open my account is if their XXXX department says there was a problem. However the IT department does not seem to understand the issue because they keep sending me letters telling me when I made the {$600.00} payment and that my payments were applied to my account on XX/XX/2016 but then returned by the bank not addressing the problem that I did not schedule a manual payment in addition to the automatic payment but in fact cancelled the automatic payment for no payments to come out of my bank account on XX/XX/2016. They will admit that if the payments would have never came out my bank account my XXXX store card account would still be open but they refuse to admit that there is a technical problem. They told me that my account was accessed by a computer which I told them was impossible since my computer was sent away for repairs and I accessed the account from my phone. They basically called me a liar and then finally admitted that if I hit the link on the website for full site that it would have registered as a computer even though it was my phone. There are several technical issues involved here but yet I can never get anyone to get this issue resolved because they told me that their system has never done this before and has never had any technical problems.