These people keep calling me and they always say, "Hi _____, I'm calling long distance, can you hear me???" EVERY SINGLE TIME!

I keep asking to be removed from their list and they hang up on me.  I've called this stupid number and its just an automated message saying that you've won some b.s.  Its false as I called it from two different numbers (one being work) and its the same message.  

If anyone knows how to get removed from this, I'd really appreciate it.  I'm on the do not call list (not that that means much).