This number keeps calling me, and never leaves a voice message. Some days they call two times other days just once.

I've never answered this number, I don't know how they got mine, and they never leave a voicemail.

They just called me.

They keep repeatedly calling me. I never answer but I don't know who they are.

Actually, that was easy.  Why didn't anyone call back?  OK, so here's the scoop.  The number belongs to One Touch Talent.  They are a talent agency.  If you've filled out an application or responded to a cooking show search or a game show search or modeling agency, anything like that, you might get a call from them.  Don't know if they'll try and sell you something but the person I spoke with was actually very nice.  So now you know who's calling.