Unauthorised Debit Order

Unauthorised debit order: my account at FNB was debited with an unauthorised debit order from MTN, of which i never gave anyone any authentication regarding this debit order & i don't have any business with MTN whatsoever. upon calling FNB, I'm being taken from pillar to post, being transferred form department to department without any help herewith the notes of my waiting period: FNB: 03/11/2021: 10h35: Marble from ***** department to transfer me to Debit Order department, it’s an internal call she can’t give me their contacts. Asiphe: 10h41: - (Debit Order Department: Reversal & Blocking) – transfer me to FICA -10h47: Makhosana – FICA department (not help) transfer me to cheque account department waiting… Sasha: Authenticated me on her systems (AC) – transfer me debit order department again: waiting… 11h01: Luanda: debit order, again transfer me cheque account department again. waiting…

Still after waiting & wasting my air time on this call i was not helped.

all I need to know is why was this debit order processed without authenticated collection process being performed?, reversing of this debit order will impact my credit record negatively. I frustrated at this moment, could someone please HELP me!!!