They keep calling me and when I ask who they are they hang up.  They now send stuff in the mail to my house with this number telling me I won a delta flight of my choice and a 2 day 3 night stay in a hotel.  Is this mail fraud?  I cant find the company and they will not ID themselves.  Is that legal?

This practice is illegal under the FDCPA:

Debt collectors may not engage in unfair practices when they try to collect a debt. For example, they may not:

try to collect any interest, fee, or other charge on top of the amount you owe unless the contract that created your debt ? or your state law ? allows the charge;
deposit a post-dated check early;
take or threaten to take your property unless it can be done legally; or
contact you by postcard.

http://www.ftc.gov/bcp/edu/pubs/consumer/credit/cre18.shtm

NCO financial is now scamming me by mail!  I received a postcard with "US Air" printed on the front with a picture of an airplane taking off and "Fly Away Escape" printed under it.  On the back is US Air printed at the top in a hold blue.  The body reads:  Dear (full name), Congratulatiins!  You have been selected to receive 2 Round Trip airfare to anywhere US Air flies in the continental US.
   CALL WITHIN 48 HOURS.  YOU WILL t RECEIVE AS A BONUS
   3 DAY 2 NIGHT HOTEL STAY!
To claim this special offer, simply call 1-877-830-3536

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