I was skeptical when they asked for both Zip Code and last 4 of social after I had already given them the case number they provided me.   However I was patched thru to an operator who provided enough detail about me that I new it was legitimate (or they already had the goods on me so it didn't matter.)   Then she proceeded to ask about a transaction on the card today they wanted me to verify. Long way to say this was a legitimate call.

Do not trust this number. They asked me to give them my card number without asking security questions. They sound shady. Please call your bank instead of giving these people any information.

This number (877-504-0948) called me and left a message stating who they were (Visa Fraud Prevention Services) and left this phone number.  I called the number and gave my name and the last 4 of the card in question, I was not asked to verify or confirm any transactions but was told to wait for the supervisor and put on hold for over 10 minutes. After that period of time, I figured the call was not legitimate, I hung up the phone.

This number (877-504-0948) is for Visa Fraud Prevention Services. They called and left a message stating who they were and this phone number. I called my bank to verify the number - it's a legitimate number. I called and confirmed transactions were mine - all is ok.