I get so many of these calls that I don't answer if I don't recognize the number. I just Google it and it usually leads me here. A bit of advice: if you do answer it, don't argue with these people, just hang up immediately. Pressing "1" or calling back just lets them know they've found an active number and they'll not only keep calling, but sell the numbers to other scam artists.
Chewbaca said it best......Expecting a scammer to follow the Do Not Call Registry is like expecting a fleeing bank robber to stop for a red light. Get real people if they were legit, they would stop calling you. Telecriminals do not follow the law...hello!!