promotion only causing headache

Got phone call to offer me a tablet because I was a good client, told them I would be out of the country for a week but they still tried to deliver. After I came back it took me about 6 phone calls to get the tablet delivered and already paid for something I don't have. After I finally got the tablet its not registered, so 4 phonecalls later and after following all sorts of rediculas instructions from call centre advisers still no joy because they clearly did not do anything about the problem. I want a full refund on the first month because it is not my fault I can't use the product that vodacom offered me as an thank you for being a good client, well if this is the way they thank good clients I'm changing networks.