Terrible and utterly disappointing service

What more should I do to get this contract cancelled, the cancellations department does not pick up the phone, the other contact centre answered (after a very long hold) but the agent kept quiet until they decided to hang up. TOBi can’t assist me. It’s a night mare dealing with Vodacom. If I do find an agent they refer me to the cancellations department who are allergic to picking up the phone.