Sick of calls and no one says anything on the other end!

We receive calls from this number. They ask for the owner by name. If he is not available, they do not leave a message and hang up. If they are told that I will check and see if he is available and ask who is calling, they just say it is a "business call". They get pretty rude if you press them on what the all is regarding and insist they be put through to the owner. I dialed the number back and get an automated opt-out service. I completed the opt-out from the call list, but still get calls

I keep getting calls wanting to talk with my husband & they refuse to leave a message.  They will not say who is calling or what they want.  I'm on the do not call list but keep getting these & I have opted out by dialing them back...

Calls and asks for the old owner.  I ask who he is and who his company is.  He says Carl and Specialty Graphics.  He asks for the old owner again. I tell him I am the new owner to loose my number.

I get calls from this number - first one was asking by my boss' whole name and when I said he was not in the office and asked if I could take a message I was told he would just call back next week - and I asked if there was something I could help him with as I am the Office Manager he laughed and said no, he would call back to speak to my boss.  

Now everyday, 2 - 3 times I pick up the phone - and no one answers when I answer....