This number and "invalid number" appeared on my caller ID. I picked it up, said "hello," and after a second or two heard an odd-sounding beep. I hung up. Tried reverse-calling and got message that it was  invalid. Wonder how an invalid number called me. Can they override caller ID somehow to show a false number? Of course we are on do-not-call list, but that NEVER works.

It certainly is true! Happened to me and cost me plenty. They claimed they had my recorded "yes."

OK, explain to everybody, how one 'yes' could cost you money?

They won't because they can't

They keep calling but I don't answer. Never leave a message.