Upon hearing answer machine they hung up.

Same thing here. No message. Just a hangup.

Losers refuse to respect national don't call list.

I had a missed call on my cell.  It was this number.  When I tried to call back it said "This number is no longer in service."  How do you call a number minutes after it calls you and it's not in service?!?!  This is very annoying!

Because it's either a spoofed phone number, to fake the caller ID, or they have a system to play a fake out of service message when you call them.