Who called from 9252321899

Male voice replied "Hello" when I answered, but said nothing else. Call was on for about 40 seconds.

Yes, asked for a Mr Rock.. No one here by that name, when I called the number back it said it was disconnected ... Strange

Number called me, picked up but instantly hung up.  When I tried calling back, the number had been disconnected.

I receive a call from a lady claiming that she was a friend of my mom, and said that my mom accidentally have her my number, and if I could please have her number. I said no and hung up, I called my mom to let her know and she said she didn't know the lady, I tried to call the number back and it gave me a message that the number was a non working number

Same here. I called the number back (from a blocked line) and got the recording too. It's a recording of the recording. That way people don't bother them.....