[jokh]

I don't understand what you mean, can you elaborate? Who calls the 1-800 number, and what info do they get from the call?

[stephenbez]

If you get a call from someone who claims to work at the credit card company you use, instead of trusting the caller (who could be a scammer) and potentially divulging private information, you should just hang up and call the number on the back of your card.