Called my cell phone from an unlisted number and did not leave a message. Another site says that someone from the same number left a "final notice" message on a person's voicemail. I have no idea who it could be.

If the call came from an unlisted number how did you know what number to report?

some cell phones has a block #under setting

Recieved a call from this unknown caller and they did not leave a clear message.

Received a call from this number but when I tried to call back it says the number I dialed is not a working number. So I added this to my block list.