Product: Credit card or prepaid card

This is a copy of the letter I sent to one of the CEO 's of American Express : Hello Mr XXXX, My name is XXXX XXXX. Let me say I have had the American Express Gold Card for 27 years. 
After my husband died DART switched the account over to my name in XXXX. 
I have been incredibly pleased with American Express all these years up until now. Recently I started to notice that my balance wasn't going down when I made my payments, but it was going up. During the covid quarantine, I had a chance to notice my AMEX bill. I called customer service to see why my bill was going up after making payments. They told me I was in a Pay Overtime program, where any purchases of {$100.00} or more would go to pay overtime with INTEREST. Well I was very surprised to hear this. Because I didn't need this nor did I sign for this program. And if my husband did this, I was not aware of it. I did not need to pay {$100.00} in an overtime fashion. If I buy something for {$100.00} I can pay {$100.00}. Back in XXXX the Gold card was a charge card not a credit card. 
Nevertheless, this has now accumulated from XXXX to {$15000.00}. I have talked to several customer service reps to no avail. And, by the way, some of them told me lies that they were looking into it, when in fact they weren't. This matter has been going with Customer Service since XX/XX/XXXX. 
I want the interest charges to be WAIVED and I can pay off the balance with cash today, minus the interest fees, so I can resolve this matter and stop paying these exorbitant interest rates, and get this card back to where it should be. I have paid all these years without a problem. Common sense would let people know if I had the card 27 years and been paying 27 years that I am not trying to get over on the company. I've been paying all these years, and once again, I just want to get this resolved. I told them I don't want to use the card anymore. I do not want Account Services to make any payment arrangements. I just want this resolved speedily. 
Customer service said American Express does not do settlements. I am not asking for a settlement. I do not think it is fair to charge me those exorbitant interest fees, especially when I was not aware of them. 
Customer service said I had it for 2 years. My complaint is I am a widow who was grieving at the time and made payments online to pay my balances every month, and was not aware of the pay overtime amounts, that were accumulating interest. 
I have requested to be taken off the Pay Over Time Program, but I do not want to continue paying interest fees. 
I am a very dissatisfied customer at this point. I also told Customer Service I don't want to use the card anymore and have not been treated fairly. And you are about to lose a long-time customer who would always recommend people to American Express. I will no longer recommend American express anymore if I can not get this resolved. Would you please contact me ASAP so I can resolve this matter. 
I did not include my card number. I want to make sure this is a legit email address. 
In Good Faith XXXX XXXX. 

The following is a copy of the last email correspondence I sent to the American Express Executive Customer Care office.They have not responded to it yet : Hello Ms. XXXX, I still would like to know if the recording when the DART department switched my account from my husband 's name to my name was ever retrieved.. I was told many times ( if you listen to the previous conversations with customer service reps ) that they were going to retrieve that conversation. NOBODY said back then I had to have those phone conversations subpoenaed. Now, all of a sudden I have to have those subpoenaed? Why? I was not told about any Pay Over Time Program by DART. So, now I have accrued all of this high interest rate because of this program, I didn't realize was attached to my account. I need someone to tell me what happened to my original complaint. Legally you are supposed to provide with me with this information. 
I feel like I have been lied to and given the run around, which is not fair to me, the consumer. According to the " Credit Card Act '', it is illegal to charge high interest rates to the consumer at 24 % - 29.99 %. and your practices are exactly what the Credit Card Act says you can not do to Consumers. Once again I am not trying to get out of paying for what I purchased. But I do want those accumulated finance charges waived from XXXX, when I was switched over. 
Please do not have anybody call me that does not have the authority to make these changes or have not read the " Credit Card Act ''. I want to resolve this matter today and pay off my charges minus the exorbitant finance charges.