Vodacom cancelation

I've been struggling with vodacom cancelation for almost a year with various reasons then again in October I called to cancel my router then on November 23 then the guy told me that the request was already loaded in October that there is an open order on that number for cancelation and confirning that it WILL end at the end of November.. On the first I saw there was data loaded I called them and the guy Raymond told me the order was never processed and that he wil log a call for cancelation and a credit note . Yesterday a lady contacted me to tell me my contract is now R650 because I didn't upgrade or cancel in time.... So I called the call center again *** to be told stil nothing has been done So now what do I do because instore they cant do it over the phone they don't want to so who do I contact? Must I seek legal help because this is not the first time this same call center did a ********** upgrade on my name after saying NO muliltiple times so please assist