Vodacom drag feet to cancel contract

Vodacom is charging me for services canceled. I phoned and asked person " Samukiliswe' on the 28 June requested the cancelation but it was not canceled. Phoned again on the 27 July because i realized it was not canceled. Spoke to Lee again she did not cancel. Phoned again on 27 Spoke to Angel again not cancelled Also spoke to lady Noncobeko also not cancelled. Only on the 28th a gentlemen cancelled the contract.

Why must i pay for a contract that was supposed to be cancelled. I believe the agents are working on commission for contract retained and therefore they don't want to cancel any contracts