I keep getting calls from these people. They leave messages asking for a certain person (not me, and no one I know). I was home for one of the calls and the woman was very rude, asking if I know that person and how long I have had my phone number. When I asked where she was calling from, she refused to answer and I hung up.
I received several calls for somebody else from this number. When I called back, I found out that it was a collection agency called Global Credit & Collection. I found there website ( http://www.globalcollection.net/Consumers.aspx ) and contacted their main number. They told me that they would remove my phone number from their files, and they did.