I got the same call.  They started pushing I had won something, they were phishing for account info.  HERE'S HOW I HANDLE THIS PEOPLE.  At some point I say the following...."Look (Vijay, Rashid, etc.), at this law requires me to tell you who I am.  I am a Deputy U.S. Attorney and my job requires me to investigate companies like yours for possible prosecution, so do you want to continue this phone call?"

EVERY TIME I get an immediate hang-up...and rarely do they call me back.  Don't forget to say those words in a stern tone.  You could also say you're a Deputy Attorney General in your state, or an Assistant District Attorney in your county....it should all work.  Remember, sound authoritative in your voice!