I was late on a recent Amex payment. So I get this called, "XYZ from Amex here, need to speak to you about your card". So I say sure. Then she says "we need to ask you some personal details to confirm your identity". I say no. She says huh? I say no - you called on a no caller ID number, I have no idea who you are, so I refuse to give you confidential information. She then proceeds to tell what its about anyway LOL.
Seriously, banks/card companies need to tidy up their act.