TELKOM CANCELLATION

Can Telkom please tell me why they are debiting my account when it was cancelled for end of December 2019 but from Jan 2020 till now they are still debiting my account and I have to reverse all the time. I HAVE NOT HAD DATA FROM TELKOM SINCE MY CANCELLATION DATE 31-12-2019!!! I WANT THIS TO STOP,SORT THIS OUT TELKOM I DON'T OWE U ANYTHING!!!