I WANT TO CANCEL MY CONTRACT

I received an sms telling me to subscribe for airtime at discounted price every month for 6 months. It was not stated as my numbers will be changed from prepaid to contract, I was not satisfied at all as my number was changed from prepaid to contract without a verbal consent despite the reply to the sms. I have been calling RMCS since last week trying to cancel this contract with no luck I'm being promised a call back from a cancelation department but I never receive a call. Even today no one ever got back to me to cancel this contract., I am thinking to pay up my Edgars account because of this thing and close it.. Please help I really want to cancel . Even on Monday I called, they promised to get back to me within 48 hrs for cancelation, even today I'm still waiting. I can't use whattsup and my caller ID is private and I am not even getting calls, phoned Vodacom to enquire and I was told that they cannot help me as I do not have contract with them.