Beware of Vodacom agents

Never ever upgrade with a vodacom agent who phones you! It has been ages since I have upgraded my contract with a handset, and apparently I have upgraded the contract in November last year, which is now news to me. I have also tried to cancel, by e-mail to customer care, numbers and services not in use but this is ignored. All they want to do is keep you to a contract. From now on I will not even answer a call from a Vodacom agent to supposedly wants to give me a better deal