I always get unwanted phone calls on my work-supplied cell phone and I have never given out the number to anyone.  (It's really just a pager.)   I have put this number on the DNC list but apparently that does little good.

I ignore the calls.  I get one with a different caller ID each day at about the same time of day.   But, should I ignore the call immediately or let the phone ring until it goes to voice-mail?

I think this is a new start-up.

Got a phone call (4:24pm) from an out-of-state number that I didn't "know" or recognize.  
(Does this mean that they are involved in Interstate Fraud?)  
They, of course, left no message.  
As always, I didn't answer, but looked up the number here.  

I am on the National Do-Not-Call List, and have been for over a year now.  
(I guess this is our government at work for us.)  

I'm going to
http://www.fcc.gov/complaints
AND to
https://complaints.donotcall.gov/complaint/complaintcheck.aspx
and see if that can get the government to work for me, and stop these calls.  
(Yes I will go through all those steps.)  [I have also bookmarked these URL's.]  
I have also assigned a silent ringtone to this number.  (I am up to 41 now.)
We should all pile on.

Got another phone call (9:32am) from an out-of-state number that I didn't "know" or recognize, that I have marked in my contact list as a "Telemarketer" with a silent ringtone.  (This number is #43 of 44 so marked.)  
(Does this mean that they are still involved in Interstate Fraud?)  
Once again, they of course, left no message.  
As always (especailly with numbers marked as "Telemarketer"), I didn't answer, but looked up the number here.  

I'm still on the National Do-Not-Call List, and have been for over a couple of years now.  
(I guess this is our government at work for us.)  

Once again, I'm going to
http://www.fcc.gov/complaints
AND to
https://complaints.donotcall.gov/complaint/complaintcheck.aspx
and see if that can get the government to work for me, and stop these calls.  
(Yes, I will once again go through all those steps.)  [I have also bookmarked these URL's.]  
We should all pile on.  (I certainly am.)

This is USLIFEFORCE...again...they have a new number. If they're spoofing a U.S. number but calling from overseas, they have found a way to get around the Do Not Call list. Most of these numbers are either disposable numbers, shell numbers or spoofed numbers. The DNC can't do anything about these foreign callers. The DNC only covers legitimate, U.S. based numbers that violate the law. These guys operate outside the law.

USLifeForce's old number was 206-743-0981. They went from a Washington area code to a New Jersey area code. They must have been caught on the other number, so switched to a new number. Probably an offshore operation so the DNC can't pick them up.....

I use my Centurylink Call Blocking Service which lets me block up to 20 numbers.