I am sick of these phone calls.  The phone number changes every time they call, but they are always 919 area code, then the next exchange begins with 6xx.  Then the last four digits change.  They start in the morning and call every couple of hours during the day (at least they don't call all night).  When I answer, an automated message says "good-bye" and hangs up. They never leave a message.  I have called back sometimes and it is either disconnected or somebody answers who has no idea what I am talking about.  It is obvious they are using something to make the phone number appear in caller ID that is not the number they are calling from.  I don't know why they do this, other than to see if my phone number is a valid number or not.  I have filed a complaint with the NC Attorney General's office, but who knows what will come of that.