Terrible service to cancel my VODACOM contract

I cancelled my contract on the 16th of July the agent advise that the contract will cancel on the 4th of August and I will only be charged pro rata until the 4th. I have spoken now to 6 different agents from Vodacom and ALL calls are recorded and each of them have a different story. Requested them to log complains with no luck! Again receive an invoice for a full month subscription with no idea for which month I am charged ! The last agent logged a complain and said someone will phone me back the same day. This is now 5 days later no call !!!! She gave me a number to call back. The number se provided me belong to Discovery