Appalling attitude has me thinking this is a ****

So I get a call from a Thembi Phokobje who claims to be from FNB, says she's calling regarding my "bond". Doesn't even ask me if her timing is convenient for me as a client and immediately demands my I.D number. In this age of ****s, who divulges their particulars over the phone, especially if they called you?! i tried to explain the reason for my hesitance to her and asked her to verify herself for my peace of mind. needless to say, the consultant failed to explain herself and just became rude, so i ended the call. I need an explanation from FNB