Vodacom not canceling service and keeps debiting my accout.

I have 2 contracts with Vodacom and one came to an end July-August 2020. Vodacom employees kept on calling me to extend/renew my contract as my 24minth contract was coming to a end and that I will be billed more for the same service on a month to month. I advised them that I would like to cancel the contract as I have another one avtive with them. The service was not canceled and I noticed that the money was deducted from my account. I then sent a mail to *** on the 9th September 2020. In October I noticed that the money was still being deducted from my account. With a strugle I got hold of the cancellation department and the employee advised that he was going escalte the matter to get the fees credited to my account. I did not get any feedback for 2 weeks and called again. 2 day afterwards another agent called trying persway me not to cancel. I explained my situation again, but still they have not canceled my service and still they debit my account. I can't block the debit order as I have a additional active service which also gets debited.