********** debit orders, worst service ever

I haven't been a customer at Cel C for many years, but still there is debits from my account every month varying from R98 to R436 and i cannot seem to put a stop to this, I've spoken to numerous operators for hours this week alone without any joy, I've managed to log a query and got a reffrence no. And still nothing, they would have sent me emails and contacted me within 2 working days witch never happens and the gave me the number of their legal department witch was the number for RCS general queries, beyond frustrated, they are *****ing my money ********ly and there nothing i can do about it, as soon as i stop the debit order they just put in a new one on a different amount.