Deduct debits after account has been closed

Good day,

I am upset about the service that I have received from MTN. After settling my account in full and after being notified that my account has been closed by Mapitso Skhosana there were debits being deducted from my FNB account. I would like to know why this account has not been closed. I am currently in NZ, the only way which you can reach me is via email. This is a horrible service and I am not happy at all!!!!