MTN SA is ripping people off!

We have been trying to move from contract to prepaid since last year, we have gone through all the guided processes they said we should even had their legal department who also told us what to do, which we did. It is now 8 months fighting the same battle, being told we owe money on a contract we haven't used, 1 number we don't even have a SIM card because we can't sim swap, they say we must pay. We haven't used the numbers??...this is very unprofessional! We are still having to start again? When will we get action?