Vodacom are useless

My contract was due for an upgrade so when I received a call from vodacom I gave them the go ahead to upgrade it just for them to give me the wrong deal.. I have spent the whole of February trying to get the problem resolved but they keep on making me do 10 different things and every single person I spoke to for help acts like they want to help but none of them ever get back to me... Now for the next 2 years I have to pay for something that I don't want