Payment of account

I've requested from Vodacom to remove the debit order now 3 times and this has still not been done. I pay cash every month at the Vodacom store in east gate. The debut order still bounces and I get charged R100 every month extra due to Vodafone lack of competency. I received a SME last week for the bill not being paid and received 3 call already today from Vodacom with the voice prompt that the bill is not paid. When I contacted the customer care centre I was told the bill is up to date. But still Vodacom phones me with the voice prompt. I received a statement yesterday with the new amount due at 31/08 with the amount paid reflecting on the bill. So what is the problem with Vodafone accounts department? If they don't overcharge me and pass a credit they ***** up my bill. I never receive a phone call that explains why I was overcharged and then credited but when you don't pay Vodacom is quick to call. I want to cancel all my co tracts and go to another network that actually knows what they are doing with their customers bills.