Impossible to cancel 3G contract with Vodacom

Terrible service from vodacom. I have been trying to cancel my 3G contract for the last 5 months with no luck! Since June i have been calling them monthly to cancel my contract as i no longer need the 3G data and every month i am told that it has been cancelled, only to find that the money still goes off my account on the 1st of every month. I even went into the vodacom store to cancel it and they created a request for the cancellations department to call me, this was 3 weeks ago and im still waiting! Such a waste of my time , energy and money to have to call them monthly and deal with their incompetence, surely it cant be SO difficult to cancel a contract! Nobody ever calls you back from Vodacom! Shocking service