There was a message left for me from this number. It was to alert me of a possible credit card problem. They left a call back number of 1-800-690-8056.
Instead of using either of these numbers, I called customer service at my credit card company. The call WAS LEGIT. They cancelled my card and sent me a new one.
Seemed legit. They justed asked to verify that I made a purchase in the amount of $xx.xx. They didn't ask for any account info and I didn't give any account info.
I don't think anyone could do any harm with knowing the amount of a single purchase. Actually, they already knew the amount before talking to me -- I just gave one "yes" response and that was it. In fact, if it was a fraudulent call and there was something they could do with knowing the amount of the purchase, they would just go ahead and do something rather than call me to confirm the purchase.
This is not CITI Bank, but it is Mastercard's joint fraud center (for accounts with CITI and a few other banks). They are legit. I'm a cop and I use them for fraud investigations from time to time.