Pathetic Service from Retentions

Vodacom does not even deserve 1 star rating. A simple cancelation of a contract seems to be impossible with them. I have phoned in about 7 times in the last 2 days and nothing gets processed or done when promised. I was told a team leader would contact me within the hour, its been 36 hours and im still waiting to be contacted. When I asked to be transferred to the escalation/complaints division, I was told there isn't one. Do I need to further explain why I want to cancel this contract with Vodacom...