Vodacom incorrect bill and now won't give my money back

Vodacom incorrectly billed me by double billing me for my device and data, they also added insurance to my contract that I never asked for. I called in and they assured me that everything will be reversed and paid back into my account only to find that the following month my bill was 7000 so what happened was they cancelled my device by accident when cancelling the insurance and so they passed the credit notes but used the cred that went to my vodacom account for some damn reason and not my bank account to settle the device, I called again and they assured me everything will be fixed before my debit date, which was not I called again they said they will fix it so that my new bill reflects the correct amount and that the money is paid back into my account, I called again and they advised it will take 14 days, here we are on the 3 months later and I called again but now they say my credit was use to settle the device but the device has been re-instated but I still do not have my money that was debited from my account!!!