I Took this call because it was a local number. It was nothing more then the old Robo call for a free cruise. This is due to the silence I got when I said that this was a National Do not call number.
This number is now blocked
Simple. They program a computer to call all numbers within a certain numeric perimeters. Then they harvest the "good" numbers and turn them over to the phone scammers. About all you can do is block the call.