I've been getting multiple calls on my cell phone, usually early in the morning (and I work nights) from this number:  214-253-2952.  After a couple of weeks I called -- their message says they are "Subscription Sales Inc., an international company that sells newspapers across the United States" (uh, aren't 'international' and 'across the U.S." two different things? Idiots)                                                                                                                  

I left a message telling them to desist and that I was reporting them.  Then registered the number with the "Do Not Call" national (or international, in their world).  And then I called about 50 more times and left blank messages on their machine -- not that it will do any good, but it felt satisfying.