Vodacom does not help sort out my account!

How do I go about?

I asked vodacom in March that I want to cancel my contract, I had to fill in a cancellation form, then got a cancellation quote of over R10000, the next day I paid it up in full? They send me email that the process was complete, so I got a new contract the following month on a new number! They are still billing me for that contract and after 16 times of queries I have put in with them, they are still billing me.....who can help me sort out this mess if vodacom doesn't do anything about this! It is busy damaging my credit ability and nothing seems to be done! I even asked for all of my telephonical phone call recordings which I also dont get any feedback of!