The person calling must have our officers numbers.  When an admin answers they don't say anything and hang up.  I mean they call them call one after another.  If the person is not it I just punch the button and their line is tied up until I hang up.

I just got a call from him so i tried to find out who the guy is. I recognized this voice because he called many times already and when i told him that my big boss based in another country. He will say "Oh Sorry" and hung up.

from now on, if i see this number shown up on my office phone again, i will say directly that many people complained about your calls!!!

got a call from this number, claiming to be from Lade Law (?) investment bankers in new York with headquarters in London. Whether I wanted to invest.

Also received a call asking for my name and hanging up. Why would someone (called Mark Blaha) do this?

Just received a call from this number.  It seems like they are confirming that the person is reachable through that phone number...thus giving value to their phone numbers list, possibly for resale.

This person called looking for the business owner (asked for him by first and last name).  I told him that he wasn't here and, "Can I take a message?"  

The guy said no thanks and hung up immediately.  Very annoying that they waste your time like this.  He's probably trying to tell us that we qualified for a line of credit up to a quarter million dollars at a low 4.9%* (asterisk) APR.