Defective customer service

Vodacom services has deteriorated and has become below par to say the least. i logged a request to cancel an upgrade within the cooling off period. They assured me request was logged and two calls later escalations logged and that confirmation within 48 hours but nothing happened. I requested cancellation on three calls with a Nareesha, Nobuhle and a Chantelle but nothing was done. I'm now charged for a contract i requested to be cancelled within the specified time for cancellation. No one is coming back to me and there is no written communication whatsoever from Vodacom. Further no reference numbers were provided.