I got a call from this number and let it go
to my voicemail. The woman who called said she was from citibank and was calling about a fraudluent charge. I didnt trust the number so I called citibank at the number listed on my card. They said that the 904 number was correct and it was their fraud monitoring division. Turns out someone
tried to use my credit card number online. If in doubt, just call the number on your card.
I got a call saying it was MasterCard fraud early warning as well. I don't have a MasterCard. This is the second time they have called me. I didn't answer the phone ether time so they just left a msg. If I do answer I sure as hell wont give them any info.
My wife got the same call asking for me: heavy accent, almost impossible to understand. I'm in Mexico this week but have only used a VISA card so there's no reason to have me call about a MasterCard.