No stopping unauthorized debit deductions

*****ulent debit order by MTN reported more than a year ago. Following up on this monthly. Bank knows it is a *****ulent transaction, but can't stop it. How is it possible for someone to deduction unauthorized money from your account and the bank cannot stop it? They write it back every month, but this amount increased now to over R45000 a month. Who has that kind of money? So it is putting us in a cash flow pressure and bad credit situation. No one from the ***** department has been in contact. We have done everything our banker said. Reported to police, reported to MTN head office - still goes off