Unrecognized number, no callerid, no message left.

- received call from 763-424-9451, Minneapolis, MN
- no message left

I answer, because of course I answer.  The live ones are fun to play with.  But it's just a robocall that says "I'm sorry, that's not a valid extension. Please try again." and hangs up.  How boring.  Scammers are so popular now, everyone's doing it.  Without testing first.  Morons.

Called my cell phone. Caller ID read "Minneapolis, MN". I didn't answer. They left a voicemail that consisted of about 3 seconds of a high pitched tone. I blocked the number.

Usual stuff.  Call from random city , no message.