Cancelletion error

Vodacom phoned me to upgrade my existing contract to a cheaper contract.I accepted it but the next day I decided against it and cancelled it telephonically.However my attenpt failed and my cancellation was not logged.On the 20th November I spoke John in the cancelation call center and he logged the cancellation.On the 30th I spoke to Godfrey in the customer care call center but he revered me to Sandra in cancellation department.She asured me it will be cancelled on the 1st of December.The 2nd December I spoke to Jenelle she logged the cancellation again.However it was still not done.I went into the Vodacom shop to ask one of the consultants she was very helpful and loggend multiple request to reverse the contract and cancel it.Her attempt failed.It seems it is impossible to cancel a contract at Vodacom.Their customer care and cancellation center service is of poor quality and not up to standard.If I could give 0 start I would.