Unhappy client with Vodacom

I have been trying to cancel my contract with vodacom since September, because the contract would have expired in October so I followed their procedure of giving a one months notice but my contract still hasn't been cancelled and the agents at the Vodacom retentions call centre have been of no help its either the drop the phone without resolving my issue or promise it will resolved and nothing has been done to date, now they have recently debited my account with an amount I never agreed to which I have reversed, but reversing debit orders will have a negative impact on my overall credit score... Can Vodacom please just terminate their number because I have served and honoured my agreement with them for the term of my contract. But now their wrongfully retenting customers by not adhering to my request of cancelling my contract.

VODACOM'S SERVICE IS VERY POOR