They phoned but would not leave a message or name on display. I refuse to answer calls from numbers I don't recognize.

Are you sure you haven't registered your number on the 'Do Call' list by accident? It happened to me, I kept getting these calls until I made a complaint and it was discovered my details somehow got entered on the 'Do Call' list, instead of the 'Do Not Call' list. Check with your telephone service operator if you are unsure.

they call, then when i answer the line goes dead.

Called on my cell which of course is registered on the Do Not Call List

Got a call from this number  won't answer a call from a number that I don't know.

Just got the call, silence on the other end, so I just hung up. Three times in a week is $500 for me, hope they try again twice.