This number called me and when I picked up he/she put the phone down and when i tried to call back its a busy tone..

They called my cell phone about a sweepstakes entry for having/using a Visa, MC, Discover, or American Express card.  
I just got my new cell phone number three weeks ago and this company had my name and knew the city I lived it.  She said they purchased my number from one of several comapnies.

This number has been calling me for WEEKS!  I've got both the hangup and the sweepstakes

This number has been calling me a lot. I never answer because I dont answer 1-800 numbers but when u call back its busy.What gives? Also they leave no message.

I received a call from this number just now and when I answered, they hung up. Weird.

they call me few times a day but they dont leave any message. when call back, it's allway busy

I have received an incoming call from the above # every day for the last several weeks and sometimes more than once a day and evenings. I answer and the caller hangs up. I try and call back and get a busy signal. FOUR TIMES YESTERDAY!!!