Uncanceled Cellphone contract

I had a contract with Telkom which expired in March 2018 I did not notify them that I was not going to renew the contract and then that was my fault and they continued to debit my account. In August 2019 I went to a Telkom outlet and told them to cancel that contract and I paid the amount that was outstanding which was R880.00 (paid in September) then it stopped but to my surprise in November they started again debiting my account and I have been reversing the money from because I instructed them to cancel my contract. Last month they debited more than a thousand rand from my account again. I live far from town and I haven't been to their outlet again for same thing. I feel ****** to pay services I no longer use.