Passing the buck with query still unresolved

Ive called Vodacom more than 20 occasions, spoken to more than 20 ppl and every time I tried to speak to the same person that person doesn't exist and I have to explain my story again. I phoned on 19 March and its now 20 April and more than 20 calls later and my query still not resolved. There is nothing left for me to do, but cancel it as soon as the contract ends, as I don't want to be part of a company that keeps passing the buck and not even the supervisors can help me.