Cancellation department - No answer

The cancellation department refuses to answer their phones, I've been trying to call them everyday for a month to cancel a contract, but no answer. I've been to the Vodacom shop to try and cancel it from them, but for some reason (lack of advanced use of thought processes) they cannot cancel from the shop, you have to call them. But when your account is in arrears they will immediately call you to get your money. Is this a smart way of forcing people to keep paying money for a service they do not want? I would like to get a response from you by phone call. I do not want to get the automated response.