Account Dispute

Vodacom has debited my contract twice for the past 4 months. I've been going to the Vodacom Shop and they have been talking to the call center several times with no help. They have come in contact with one of the Call Center Manager. He requested the supporting documents which was sent to him beginning March 2020. Still they haven't come back to me. I requested a FULL refund for the 4 months which calculate to almost R 8000.00 and nobody comes back with a resolution. They just debiting by account (taking my money) but do not want to resolve the problem.