Calls at all times of the day

They call all the time. Caller ID says CCI. Whatever the hell that is. I do not or ever will answer a call from a name or number I do not recognize. What gives them the right to call and bother us.
DNC list is another joke from our government.

CCI.  Annoying scammer call.  Calls many, many times a day.  Leaves no message.  I guest they don't get the message we don't answer numbers we don't know!

I am on the national do not call list.  I have reported them numerous times!  I also have call "blocking" with Vonage.  They have been put on the "BLOCK" probably 10-20 times, by me....and, yet...the exact same number keeps getting through.  I even called back (of course, you can NEVER speak with ANYONE)....left them a DETAILED message explaining all that I've written here, and requesting that they STOP calling!!!  They call anyway!  FRUSTRATED BEYOND BELIEF!!!!!!