DEDUCTING MONEY FOR NO REASON!

Wish I could give 0 stars. We only have a wifi contract with mtn and upgraded it once since they phoned and told us the contract is about to expire. We upgraded in November. Since March mtn tried and deduct R4000 and something from our account and when we phoned to ask why, nobody could tell us and we need to go in-store to sort it out. Went in-store which is 200km away only to find out that it was for a canceled contract, but never had another contract before. We recieve otp 's at 5 o'clock in the morning, so maybe someone tried and open a contract on our name.. called the ***** department, they laughed at us, saying it's impossible. Few months went by and they tried every month to deduct the money which the amount is getting bigger. Phoned again, talked to the accounting department. They don't even know what the amount is for. Last night they suddenly put the wifi off and then the amount was for a clawback , so for when we upgraded we needed to pay that for early upgrades (but they phoned to tell we needed to upgrade or our contract would expire). No one told us that we needed to pay that and they only tried to deduct the money 5 months after the upgrade. So can anyone at Mtn SA tell us why we have to pay R7000 now????? Everyone has a different story and seems no one knows what is going on.