Product: Credit card or prepaid card

I submitted a Bill Payment using American Express National Bank on XXXX to pay more car loan with XXXX XXXX XXXX in the amount of XXXX. I have paid using this method in the past. However this time XXXX never received the payment. I contacted XXXX on XXXX and was told that I needed to submit a copy of the Check that was sent by American Express over to them in order for them to locate the check. I contacted American Express on XXXX and requested a copy of the Check. I was told that it would take 24-48hrs to receive a copy of the check. On XXXX I received an email from American Express stating that they received my dispute of the XXXX payment. I called and spoke to XXXX in the XXXX on XXXX and explained that I never requested a dispute. That I just simply needed a copy of the check that was sent to XXXX XXXX XXXX. The representative stated that they can not produce a copy of the check without a dispute. I asked why if there was in fact a check sent then there should be a copy on file. The representative stated that she would have to check with the Back Office to see if there is a copy there and she would get back to me. She stated that if the Back Office could not provide a copy that I would receive a copy within 10 business days. On XXXX I received an email from American Express that stated You may request to have this payment stopped and refunded to your account as the check has not cleared. If you wish to stop this payment please respond requesting to have this payment stopped and refunded. On XXXX I called American Express and spoke to a representative about stopping payment of the Check after I confirmed that XXXX still has yet to receive the check. The representative stated that she went in and canceled the Check after I replied to the email confirming that I wanted to stop payment of the check. The representative assured me that the process required one day to process the stop payment of the Check and 2business days for the funds to be returned to my account balance. I called back on XXXX and was assured that the funds would be returned by XXXX on XXXX. Today is XXXX and the funds have not been returned. I called American Express this morning and spoke to a Manager by the name of XXXX. She is now saying that my funds will not be returned to my account for up to 45days as the dispute investigation is on going. I explained to her that I requested a stop payment of the Check. I never requested a dispute and that I was assured that I would get my funds back 3days after the stop payment request. The Manager just keep referring to the Dispute process. I asked her if she needed for me to forward the email regarding the stop payment over to her. She stated that it was not necessary. However she would not speak to me in terms of a Stop payment of the check. She only would speak to me about a dispute that I never requested. At this point it has been 31days since the XXXX was taken from my account balance. My car payment is behind more than 30days. And I do not have Money to make a payment to replace the payment that XXXX never received from American Express. And now they are telling me that its going to take up to 45days for me to get that money back and are refusing to honor my stop payment request. I don't know what else to do.