Received a call on my cell a few minutes ago but didn't answer since I was busy arranging for my 2.7 million dollars to be sent from Nigeria.(Ha!)
Seriously, there is absolutely nothing you can do to permanently stop these calls under our current laws. The "Do Not Call List" is only for calls originating in the USA and these calls come from India and other foreign countries. They spoof the caller ID to show a USA number but that isn't where the calls come from. When you block the number or even the area code, you really aren't blocking the caller. They will simply switch to a new spoofed number.
The phone companies don't care because they make money on each call.  
The only solution I can see is to have laws passed that require the phone companies to reject all spoofed numbers. But the criminals will probably find a way around that.