Product: Credit card or prepaid card

I hope that I can get help in resolving a dispute I have had with Bank of America for almost a year now regarding fee charges of {$380.00} on a XXXX  credit card. 
None of this {$380.00} is for goods or services that I received : They all relate to Bank of America application fees and late charges invalidly applied. On XX/XX/XXXX, I purchased a train ticket from Amtraks online reservation platform to travel from XXXX XXXX to XXXX XXXX to visit my sister ( Reservation # XXXX ). I was not able to make this trip due to documented medical complications related to a XXXX XXXX that I had suffered. XXXX fully refunded the purchase price of the ticket to Bank of America. It took several months for me to complete all of the paperwork requested to have the train ticket purchase cancelled. 
I have been trying for over a year to get this matter solved. I have had numerous conversations with Bank of America agents by phone who all say the application/late charges should be reversed, but somehow this never happens. I even have recordings of telephone conversations with Bank of America agents who say these charges will be reversed and the steps that I should take. The most relevant of these conversations took place XX/XX/XXXX and XX/XX/XXXX. 
I have never received any notice or communication from Bank of America as to why the agreements reached with their agents by telephone were never honored. 
I have sent written communications to Bank of America regarding this matter, one of them at the specific direction and instruction of a XXXX agent. 
I have never received any response from Bank of America to any of my written inquiries. I have never received an explanation as to why they are justified in charging me almost {$400.00} in fees when they received a full refund of the services purchased. 
Now, during the last telephone call I made to XXXX I was informed by XXXX manager XXXX XXXX that my case has been sent to collections, based upon a decision made by some XXXX department called the Executive Escalations and that I have no further recourse but to pay the bank charges and live with a ruined credit history. 
This is all very unfair. I have been calling and calling and writing to Bank of America for months trying to get this matter resolved and I have never received any written communication from them regarding this matter. I wrote to or spoke with XXXX agents on XX/XX/XXXX, XX/XX/XXXX, XX/XX/XXXX, XX/XX/XXXX, XX/XX/XXXX, and XX/XX/XXXX. I wrote to XXXX Headquarters XX/XX/XXXX and XX/XX/XXXX. During the repeated telephone conversations, the XXXX   agents all reviewed my account records and said the bank fees and charges should be waived, according to XXXX policies. I have recordings of these conversations. This never happened. Then finally, I was told at the end of XXXX, when I last called, that this XXXX  Executive Escalations unit had made an arbitrary decision behind the scene to maintain the bank charges and refer my account to collections. 
I must restate and emphasize that I have NEVER received any written explanation or communication from Bank of America regarding my repeated inquiries. XXXX has never explained the rationale or justification supporting their decision to keep almost {$400.00} of their customers money when they had received full refund from their partner, XXXX, for the services purchased. This is not right. XXXX  is taking advantage of the old and infirmed. I am a XXXX-year-old senior citizen who lives on Social Security. I can not afford to pay almost {$400.00} from my meager income when I received nothing of value for that money. Moreover, almost as bad, my previously excellent credit history has been ruined by this transaction and now I will have to pay even more for whatever I buy on credit in the future. Bank of America was fully reimbursed by XXXX for the price of the train ticket that I never used because of medical emergency. It is not fair nor right that they now get charge and keep {$400.00} for bank fees that purchased nothing. Can you please help me to get a fair hearing on this matter? 
Most sincerely, XXXX XXXX