Product: Credit card or prepaid card

Earlier this spring, I applied and was approved for the American Express Everyday credit card which I planned to use for a balance transfer. The American Express card held a promotional period of 0 % interest for 18 months for any balance transfer that was completed within the first 60 days of opening the account. I planned to transfer a {$3700.00} balance from a line of credit I had with XXXX XXXX. Before executing the balance transfer, I wanted to be sure that I could transfer a balance to my AMEX card from a line of credit ( not a credit card ). I spoke with a customer service representative from American Express on their chat window feature and fully explained the situation. I was told by the representative that it WOULD work for me to do a balance transfer from a line of credit, and to just enter the account information on their balance transfer page. I did this, and after a few days I saw a new balance of {$3700.00} on my AMEX Everyday card. However, my XXXX XXXX balance was unchanged. Confused by this, I reached out to American Express customer service to get an answer, and was referred to the balance transfer team. What I found out was rather disturbing, that I was given the wrong information about transferring from a line of credit rather than a credit card. Rather than transfer the balance from my XXXX XXXX account, the AMEX system took the information I entered and ended up transferring a balance from a random XXXX XXXX store credit account I am in no way associated with. They essentially sent XXXX XXXX {$3700.00}, and put that balance on my AMEX card. This was frustrating, as I knew that this situation would not be resolved in time for me to do that correct balance transfer during their 18 month/0 % interest rate promotional period. After speaking with both AMEX customer service representatives and members of the balance transfer team, in late XXXX and on XX/XX/XXXX, I was told that they would resolve the situation, make contact with XXXX XXXX, and have my AMEX balance removed. Since this balance was not mine, they told me that I wouldn't have to worry about paying for it, to ignore any past due notices because they would resolve the situation. Two months have gone by, and situation has not been resolved. The balance is now at {$3800.00} because of past due surcharges, and I just received a notification from American Express that the account will be going to debt collection in seven days. I have spoken with both customer service representatives and members of the balance transfer team again, and it seems that little to no progress has been made with regards to AMEX correcting their mistake and removing this XXXX 's balance that is not mine. The AMEX representatives claim they are working to get this resolved, but when I ask them what will happen when the {$3800.00} is sent to debt collection they have no answer. They continue to send me back and forth between their balance transfer team and customer service representatives, both claiming that this problem is out of their control. It is incredibly disturbing to me that American Express was able to send a balance to a random, unnamed account unassociated with me, and even more disturbing that they are taking so little action to get rid of this balance, but rather, giving me past due notices and sending it to debt collection. It is not my debt to pay, their system made an error and their inadequacy and incompetence in correcting their mistake has put me under significant stress and may potentially damage my credit score. I am worried that if the account goes to debt collection, it will make this issue that much more difficult to resolve as this {$3800.00} balance will no longer be associated with AMEX, and the balance the debt collection agency will be asking for will now be bigger than the {$3700.00} AMEX will get back from XXXX XXXX ( if they ever DO get this resolved ). The only  solution they have offered me to prevent the account from going to debt collection is to make the minimum payment ( {$180.00} ) despite the fact earlier on their customer service representatives ensured me I would not have to pay on this balance that is not mine. They have offered no guarantee that I will be reimbursed should I begin making payments on this balance that is not mine. It feels like I'm being robbed of money by this financial institution due to a mistake THEY made that they are doing nothing to resolve. This has been an awful experience and I feel that I have nowhere else to turn for help, as everything I have been either shrugged off, or given empty promises by everyone I have talked to at American Express about this issue.