After 6 months still billing me and deducting mone

I have several contracts with Vodacom. Two of which I have been cancelling ever since the 2 years contract period has lapsed... I have called the cancellations department several times. To cancel these account and evertime it has not been done. Every time I call and as for proof. None are sent to me. I have even gone into a branch to cancel... and it has not been done. I have been paying thousands on contracts I no longer use, don't want and have cancelled. Vodacom is not even apologising for this! Everyone says that it has been done, and that it will not be billed again and that they are unable to reimburse me for the money I have paid. I want this cancelled and paid back the money.