Vodacom online

I have been trying to sort upgrade query with Vodacom since last year December. Every time when I call they tell me different stories and that the consultant who help with upgrade will call me. The consultant did not call back. The order which was wrong was returned after several calls and empty promises. I don't understand why is difficult for them to solve this problem. I don't want any contract with them because of the poor service that online is giving to customers. I want them to cancel my contract asap and don't give me any data bundles for contract I didn't agree to take.