Product: Credit card

I have been a client/customer of American Express for 20 years. 

On XX/XX/year>, after talking with a customer service person about my account balance plus any possible interest, I paid in full the balance + interest that I was told I had in my American Express XXXX XXXX ( {$2700.00} ). 

I called again on XX/XX/year> to make sure the balance in my credit card was XXXX. Instead, there was a balance in my account. The agent, XXXX, explained that there was a last charge that was being processed at the time in which I paid my card balance and that was the reason for the balance in the account. I inquired how come it didn't show when I called to inquired about total pay off. After consulting with a supervisor, the agent submitted a credit for {$63.00} ( interest ), which was approved immediately. I was informed that in XXXX hours the credit would be processed and will show in my account. He said I would receive an email about the credit, but I never did. 

The next time I called to check my account balance was on XX/XX/year>. I talked with XXXX. She could not explain to me why the {$63.00} credit has not been processed since it was approved on XX/XX/year>. It normally takes no more than XXXX hours to be processed and show on the customer 's account. I decided to pay the amount showing in my balance, which now was {$150.00} ( including the {$63.00} ). I wanted to make sure that additional interest would not continue to accumulate and added to my account balance. More interest had accumulated after I had paid off the balance on XX/XX/XXXX. The agent explained that everything would be cleared in a few days. She had no explanation regarding what had happened, but assured me that it will all be corrected. 

I called again on XXXX, XXXX, XXXX. XXXX ( XXXX ) indicated that the credit will be processed. She also didn't have any information about the delay on the processing of the credit. But assured me that in a few days I could check and it would be corrected. I would have a credit in my account. 

I called again on XX/XX/XXXX, to check my account balance and see if the credit had been processed. Instead of the credit, I did have a balance for {$2.00}. I talked to an agent ( XXXX ) which after noticing the same things the previous agents had noticed could not understand why after a month, an approved credit had not yet been processed. I asked to speak with a supervisor that could perhaps know the reason for the delay in this matter. She transferred me to someone from Research. Her name was XXXX. She said the same as everybody else. She didn't know why this has not been processed but she assured me it will be corrected and that she would give me a call once it was corrected. She also indicated that she had already credited the {$2.00}. 

I called again, and the {$2.00} still shows in my account. Once again, accumulating more interest. 

My case is just on incident lasting over a month to be solved, not much money involved, but multiply this for the millions/trillions of customers that American Express has and you get the picture. This is unacceptable and needs to be put a stop to this lack of proper service. I hope you can help in this situation. 

Thank you for your attention to this matter.