Stuck with Vodacom contract for the rest of your life??

Wish there was a minus 5 star. It seems that once you have entered into a Vodacom contract you are stuck with it for live. I tried over 3 times already to phone the cancellations phone number only to either get a robot response, or the phone being 'answered' with people that keep on talking with each other in the background and no-one answering the actual call. There doesn't seem to be any other options to cancel a contract, but they are very quick to phone you time and again to sell new contracts over the phone.