FNB turning a blind eye to ********** activity

A debit order was opened on my account (DebiCheck) although I have not authorized it...... I'm trying to pro-actively stop this debit order for a cell phone contract that is clearly being **********ly opened but no one can assist me. I'm told to wait till the debit order goes off on my account and then dispute it and the ***** department sends met to the debit order department and visa versa...... No one can tell me how this debit order was authorized and it seems that FNB is just turning a blind eye to this issues...... I have not opened any form of a debit order in the last 18 months and not handed any personal documents to anyone in this time and it seems like someone internal to FNB is involved........