I just got the same, the name Alex (from the post above) rings a bell from a real A**HOLE that when I tried to hang up started getting lippy and I got hostile and he started making threats he would make my life miserable. They have numbers all over the US that they use to call you. SCUMBAGS.
this number called they called answered and they hung up! called them back and i asked who they were. They said it was "Mike" and then they asked who I was, I told them I was not going to tell them untill I was told the reason for there call! He then hung up on me.