And they try other scams too!  Like sending you a letter telling you that you have 2 free round trip airline tickets anywhere in the continential US. Thinking this was funny as no returen address on the envelope (1st hnit this was a flimflam) I looked up the phone number in the letter and saw this site on the internet.
Thanks for the heads up guys! I'm not about to call this number and let them have my number in their data base!
Oh and by the way, if you get a letter form US Airlines there is no such company! The real one is US Airways !
Here is a link to the other site telling you the letter form these crooks is a scam:

http://www.fodors.com/community/air-travel/us ... icationscam.cfm

constant calling, no message, no answer

Called mid day, didn't leave any message on answering machine.

866-820-3726
866-879-2821 ----->>> SAME ORGANIZATION ALL NUMBERS LISTED!
866-842-1465

THEY DO NOT TAKE NO FOR AN ANSWER!
THEY DO NOT REMOVE YOU FROM THEIR DO NOT CALL LIST!

  THEY DO CALL YOU UP TO SIX TIMES A DAY FROM ALL OF THEESE NUMBERS!
  WARNING! THEY DO WANT YOUR PRIVATE INFORMATION FOR IDENTITY THEFT!

A TOTAL OF 23 CALLS IN TWO DAYS! 866-879-2821 they use other 866 #'s

This Is A Scam! Finally answered and they wanted my social security number along with bank information!!!!  

  THIS IS A ID THEFT RING!!!!!!  BEWARE!!!!!

They call 7 to 8 times a day frome 7am till 10 pm most of the time they do not talk, wooo i got lucky and talked to some one he wants some money for some unknown organazation, that means SCAM, I told to take my number off the list, now I have to wait and see how good they do !!!

Have received multiple calls for over a week. Nobody there when I answer. Have now decided to not answer. How do I get rid of this nuisance? I'm on the no call list.

This number (866-879-2821) calls many times a day and just never gives up.  Still have not figured out who and why.

Was getting called by this number 5-6 times per day, everytime I pick it up and say hello and then pretend I hear nothing from the other end and pretend to tell someone near me "the phone is broke again" and hang up. the calls stopped..

This number has call me 6 to 7 time daily, so when they call I click to answer then immediately hangs up. Maybe they will get the message

YOU PEOPLE ARE ALL RIGHT  THESE PEOPLE CALL ABOUT 6 OR 7 TIMES A DAY JUST TO DRIVE YOU NUTS AND WE HAVE CALLER ID AND EVERY TIME THEY CALL I HAVE TO DELETE THE MESSAGE ON OUR PHONE WHAT A NUSICENSE, I SWEAR THEY JUST DO THAT TO PISS PEOPLE OFF AND THEY ARE DOING A GOOD JOB OF IT.

866-879-2821
Veterans charity and like others said refuse to take no for an answer

They just called here and didn't leave a message.

I have the same problem as others, they just keep calling and won't leave a message.  I as well are on the DO NOT CALL LIST!  SICK OF THEM CALLING!