Missed call to my silent number

Caller: Don't know young male (English)

Con call, claiming to be calling on behalf of the Police, something about an accident. Had no idea whom I was, obviously going to try and get that information from me. Told him the call was being traced, hung up before I could tell him to piss off.
My number is silent!

Caller: (07) 3102 1934

I had this number call our work number constantly and everytime they hang up when I answer

How the hell do they get your number? I have just changed numbers for this reason ( and it is silent) It's bloody annoying.

the caller told me that my car had an accident - I HANG UP

same, no voice at other end.

When answered, no voice on other end.