Credit card closed for 2 years and now receiving statement that a payment is owed.

After completing debt review and receiving paid up letters from Standard Bank, I receive a credit card statement saying I owe them R40. Mind you I have emails between Standard Bank Debt Review Department and myself, where they assured me that the account has been paid up and closed. Now 2 year later I receive a statement saying that I owe them R40 and the account looks like it is pretty muvh still open.