Account not closed

I closed my credit card with Absa two months ago, only now to find out that the account is still open and acruing interest. I do not understand this. I took off from work and went into the bank to close the account, I spoke to the consultant on the phone and got the exact amount to the cent that I had to pay at the cashier, and after that I cut up the card into a million pieces as they instructed me to do. Now I get a statement for R9? This is really unaceptable. Please resolve this matter as I will not be going back to that bank again to correct something that should have been done right the first time.