Upgrade by Vodacom please keep away please.......................................

I have been a Vodacom customer since 1997. This last upgrade I did is hands down the worst I have even done. All I want is to upgrade my contract without taking a new phone. It seems like that is not possible. I have called them twice now to inform them that there is something wrong with the billing. On the last call the agent told me that she's escalated the call for the contracts to be cancelled, not even trying to offer some remedy to keep me as a customer. Customer service in this case is non-existent.