Getting unwanted calls

Do you know how to find out the company name the caller works for?

number has called 4 times to and just called again at 8:45 pm. don't know who they are or why they keep calling.

they called me twice today. If I find out who this is im filing phone harrassment charges. The thing is, when I dial it back, it says its not a working number. Some scam artist thinks he can fool an American. WRONG. FBI is gonna have a ball with this one, when I report it to them..