More money that I don't know added to the money I owe

My MTN acc was handed over to Shapiro Shaik attorneys because MTN made a list with my debit Oder date ,I then made payment arrangements with these attorneys, when we did calculations with the constant my last payment was meant to be on February 2025. Today I received a call that that's no longer the case R7000 has now been added to the amount I owe without clear explanation. This seems like a ***** may o please be assisted