Confirmation of ID Number

Hi, I lodged a complaint online with FNB this morning. Someone claiming to be an FNB agent called me to supposedly inquire on my complaint. He wanted me to confirm my Identity Number which I refused but gave him the option to say it to me and i'll confirm the details, he could've opted to confirmed my birth date only however he was to quick to just tell me that he is closing the call as resolved. i asked him how would I know or confirm that he is really an FNB agent and he said to me that \well you lodged the complaint\". <br> I regard this as bad service and on top of that I lodged a complaint because my requests to change my debit order dates were not followed as discussed with an FNB agent called Omega. My FNB account is now reflecting badly because of unpaid debit orders."