Homemark Vodacom Contract

I took out a phone contract with vodacom homemark on the 6 of October 2022 and received the device in the 10th of October 2022 was not satisfied with the cell phone and I returned the cellphone and was picked up by the courier on the 13 of October I have been trying for over a month now to cancel the contract but homemark takes over an hour to answer calls or goes unanswered when I do finally get through to a consultant they tell me they will call me back with regards to my cancelation request but never do other consultants cut the call mid conversation. They continue to debit my account for a cellphone I do not have with me and I don't understand why they can't cancel this contract immediately.