Contract cancellation

My contract has expired in June. I have cancelled it on the 3 of August 2020 and ask them to convert to prepaid. My debit order still goes off. I have phoned in 4 times again now and they still did not sort it out. On the 2nd call they assured me that it has been fixed and that I would be refunded. When I followed up today (13.10.2020) again they told me it will be forward for cancellation at the end of this month only? If you asked them to check, they can see my cancellation was recorded on the 3 of August. Waiting for a response now. I will never get into contract with Vodacom again!