Product: Credit card or prepaid card

On XX/XX/XXXX, I purchased XXXX airline tickets using a Bank of America credit card. Each ticket was {$200.00}. We had cancelled our trip with XXXX, due to XXXX quarantine requirements once we would have reached our destination. XXXX was not able to resolve/refund the money for our trip, despite the cancellation, nor provided us with a refund for our tickets. 
I disputed the items directly with Bank of America on XX/XX/XXXX. I used their online dispute system, which limited me to XXXX transactions. I had to contact Bank of America by phone for the final dispute item ( which was for {$200.00} XXXX. For the first XXXX airline tickets I disputed online, they approved the credit back to my account, with no problem. For the last one, they required additional documentation, which I gladly provided to them. Since I made the call to Bank of America to dispute the last item ( which would have been around XX/XX/XXXX ), I did not receive any communication from the bank until XX/XX/XXXX. At that time, they began to bill my credit card for the remaining {$200.00} XXXX which is the disputed amount ). I contacted them by phone on XX/XX/XXXX to re-dispute the transaction. The representative re-opened the dispute. However, I had not heard anything back for months, while the balance of {$200.00} was still showing on my bill each month XXXX no minimum payment due ). 
I contacted Bank of America last week on XX/XX/XXXX to check on the status and why this was not yet resolved. The representative said she was making notes on the account, and the I should hear from Bank of America soon. 
Since that phone call on XX/XX/XXXX, I am now being billed for the {$200.00} XXXX that was unresolved since XX/XX/XXXX ) and have a minimum payment due. 
I contacted Bank of America this morning to find out why this was occurring. After being transferred to a couple of different departments, a representative told me that the dispute is under an " internal review '' with their escalation department, since it was well past the initial dispute date. I had asked why I was being billed, when I never received the services, or any credit from the original vendor. And yet, the other XXXX previous disputed transactions were approved and credited back to my card. I was not able to get a clear answer, other than being told that I had to make a minimum payment, while their " internal department '' reviews my dispute. This seems quite unacceptable, as they have already had more than 6 months to resolve this. My understanding is that they should have resolved this within 90 days of the original dispute. I asked the representative if she can provide an estimate of when this would get resolved. She said she couldn't say because it is being handled by their " internal department ''. In my view, they are well beyond the timeframe to have resolved this issue. I clearly explained to them that this was not an acceptable resolution and can not go on to infinity. And as long as they continue to leave this dispute in limbo without any resolution, they will continue billing me for the {$200.00} that was part of the original transaction that they already approved and credited me for. 

I want to inform you that this is not good customer service, and that Bank of America is taking advantage of their customers, because of they do not care about accountability. They continue to abuse the regulatory time-lines of completing certain tasks as required by the rules. 
I am hopeful that this can be resolved soon. I appreciate your help in this matter. 

Best,