Who called from 7796369869

I keep getting calls from this area code. I normally don't answer and they don't leave messages. Today I answered and there was no one on the other line. I left the line connected for a minute on speaker, and all of a sudden someone came on and said hello. I did not respond, and they hung up.

I heard on faceboom its from some kind of jail facility
but im unsure if thats true to its entirety.

They call, my calls go to voice mail. No voice mail.

keeps calling no message, when I pick up no one there. I called back and its a non working number.

They called asking for my wife. I told them she was not home and they quickly hung up. The next day they called again, when I answered they hung up without saying anything.