They keep taking the Direct Debit even after requesting a cancellation.

I was on a 1 month rolling contract with Telkom. I specifically paid the upfront installation charge (R850+) because I did not want a contract. When I came to cancelling my contract it felt surprisingly easy at first. You go on their website and request a cancellation and I even got the email to confirm that they have received my request. But a month goes by and they are still taking the Direct Debit amount. And now a 2nd month and they are still taking my money. FNB won't let me cancel the Direct Debit either because it is over a certain amount. When I call Telkom they say I have to wait until they process my cancellation and have to keep paying until then! Whenever then is. Then my account will go into the credit. Then I need to call back and request them to refund me. What unprofessional service.