Scumbag "consultant firm" translation - telemaketer.  They call you and ask you for personally identifiable information.  Hang up on them and block the number.  Believe it or not, they actually are calling from a number that you can call back and they answer.

Update: turns out they are actually scammers that are trying to get money from you. They will claim you have a delinquent account with a telecommunications service provider, AT&T, Sprint etc and try to get personal information from you in order to coerce you into cooperating with them later  https://www.google.com/search?q=Diversified+Consultants&ie=utf-8&oe=utf-8