DIFFICULT TO GET HOLD OF VODACOM

I have cancelled a two year contract however Vodacom keeps on billing me on a prepaid account. I have been calling their 082 135 line which doesn't take me to the consultants. I believe they made it difficult to get hold of them deliberately to keep customers owing them. I want to cancel their number and go to the service provider that cares, unfortunately I can't get hold of Vodacom. I hate VODACOM!!!!!!!!