MTN claim i own them money which they cant provide proof

I am a client with MTN for many years which went smoothly up to February 2021. My regular deductions are R488 pm which is for a Cell and Wifi contract. February 2021 an amound of R 1267.00 was deducted. Up to now nobody from the call center or Complaints could assit. I have up to now not received and reason for this deduction. My Wifi was switched off by MTN , after again talked to an agent the service was restored. MTN insist that we pay R657 our our services will be deactivated. I have request MTN numerous time to explain wat the money is for - NO FEEDBACK Your assistance will be appreciated, Kind Regards Gerhardus Vermaak ***

NS, I have various e mails to MTN to serve as proof