Telkom Data

I signed a two year contract for uncapped Data on fiber and all is OK. The contracted was signed in April 2018 the contract has now expired and continuing on a month to month. We have sold our house and moved to my son's farm where there in no Telkom service at all, so I have given them notice to cancel the service with no response I have tried to phone on a number of times but still no reply. Finally I went to a Telkom kiosk at the closest Mall to our farm spoke to them got a reference no and thought that would the end of the matter, but three months down the line they are still taking off R800 + a month from my account and I have been to the Bank and they say they can't stop the Debit order, I think this is tantamount to *****. Please tell me how to resolve this matter. Regards Hilton Van Dyk