call came through on my 800 number at 2:40 PM with no voice on the other end.  I called the number and got the message: the number you are calling is not in service"

I am being charged on my "800" line for a call from this number on August 21st - no one called me - or when I answered there was no one there - can't remember because I am getting so many of this type of call!!!!
This has got to be some kind of scam that callers are somehow able to use my line - otherwise known as fraud.