Telkom line cancelled - debit orders continue

We have cancelled our Telkom line last year. There was a an internet service connected, for which a debit order was authorised. After the cancellation of the line, the debit order still continued. We have raised an enquiry at the Centurion Telkom office and I have logged a follow-up enquiry on the Telkom website. The debit orders still continue and I have to continue doing stoppayments.