Lack of Knowledge

I have a contract from vodacom which has ended or could be upgraded. On the 14/0618 i had called the vodacom customer care to put through a cancellation on one of my 4 contracts that had ended adn received no joy. i kept being transferred or told that my number isnt picking up on the new system and its on the old system(like really how is the system my problem) and how can my number not be picked up eventually the 5th operator i spoke to said that it has been resolved but i have received no sms or email communication stating that this contract had been cancelled and i am still being billed for this contract. who do i talk to that has the knowledge or knows the system as to cancelling this contract