Amex Credit Card Complaint

Amex Credit card department,

Closing/Cancelling account California

in -/-/- I closed my AME- account. my balance then was $32.00 and I paid off that amount on -/-/16. Since then Amex has charged my closed account with purchases and fees for late payments now shown on my credit report of $710.00. I made no purchases after closing the account and destroyed the card. I spoke with AME- fraud dept and now am advised they credited my account with $500.00 leaving a balance that I do not owe and which will continue to incur late fees. They put me on hold for over 30 minutes and I getno response to my effort to get a - balance.