This number called me, too, on both home and cell numbers. In both cases what I heard was as if I had called someone - the phone on the other end was ringing. Maybe this is a long distance charges scam, where they bill you for a call that THEY started.
SCAM - Anyone with ideas how to report them, please post here. pretend to be collection agency and require personal information "to clear your name" - like anyone would be stupid enough to give it to them