first time call from this number, but no message left. Wondering who it is!

I get a call once or twice a week, even on weekends. I never answer, and they never leave a message.  Can't they just leave everybody alone?

Some vacation package to Las Vegas

This # keeps calling my work # and never leaves a message.

the voice mail mail box is always full

Got 3 calls today. I never answer calls if I don't know who it is, unless they are in my area code....then maybe. my phone is usually on vibrate anyway and my cell phone has become my spam number so whatever. Good luck to them. I just would like to know how they got my number? Does anyone know?