Who called from 5019770960

Just called my son's cell @ 5:38 pm in CA.  No message.

Mafia - organized crime figure... pulling of an interstate communication crime - where is the FBI? Someone needs to terminate this operation with prejudice.

calls at least once a week, never leaves a message. just called again a few minutes ago.

I just received a call from the same number,
but the name shown was:
Morrilton AR

Called, no message left on my cel.  This is irritating.  I'm getting 3-10 of these robocalls a week now.  I thought it was illegal on cellular phones?