Called me several times at work. Did not leave voice mail.

Have been calling my office daily for several weeks but never leave a message.  I screen my calls with the caller ID so I never answer their calls.

Low life calls and hear noise in the background as if they're opening squeaky doors in their house (or should trailer) then hangs up.

Called my mobile, I'd never seen the number so I did not answer, no v-mail.

the above number is Cannon Operating in Plano, TX.  they've called me quite a few times and others I know. I suspect someone at North American Drilling Corp, also located in Plano Texas, is selling client contact information which is in violation of client privacy, but that's how those shady folks in oil & gas venture capital businesses operate