Vodacom - Refusing to cancel my month contract

Two months ago I told Vodacom that I no longer wanted to continue my month to month contract with them. Today I just received another invoice for them reflecting charges for last month.<br> <br> I am not able to use the data but Vodacom continues to bill be on a monthly basis.<br> <br> They have also charged me an out of bundle amount I did not incur.<br> <br> Although I am not able to use the data bundle allocated and billed for monthly I receive sms from them every month saying that I have received 90% of my bundle.<br> <br> Stop this account immediately. I will not pay for a service I have requested to be cancelled and that I cannot use and do not want to use.<br> I want confirmation in writing from yourselves that my contract has been cancelled.<br>