FNB credit card accounts and loans not closed even after being paid up

FNB Credit Card paid up but bank did not close the account and keeps on adding interest on a fully paid account , i eas given a settlement amount last month which i paid and requested that they close the account they then imposed more interesr which i paid last week and today i see more interest was added. Unfortunately i cannot keep on financing FNB whilst I adhered to my end of the contract. FNB loans, i was given a settlement amount and paid same day and sent through proof of payment and requested that they close the accounts. I was told the accounta will be closed withing 45 days as that is their turnaround time, now there is interesr added on both accounts. FNB needs ro reverse all those figures with immediate effect and close all my accounts including the cheque account.