I have been getting several calls a day from this number.  I do not answer them.  I am also getting several calls from unknown and unavailble.  I have made the mistake of picking up the phone a couple of times.  They keep calling me by the wrong name and using a threating voice when I tell them I am not the person they are looking for.
It is my cell phone and my carrier says they can not block them.

They keep calling, but never leave a message.  If it's not important enough to leave a message, I have to figure I don't need to talk to them.  We're on the Do Not Call list.