Robo call, left no message.

I answered the phone and heard silence. After a couple of seconds, I was connected to someone with massively populated call-room background noise. He was rude and asked for "Michael"; I told him there was no one here by that name and that he had called the wrong number. Then he hung up on me. I assumed it was a debt collector, which was why I told him it was a wrong number. Blocked.

The best consumer defense on these scam calls, is to NOT give them a chance to be insistent and rude, and just hang up. Don't even debate with them.

Called them back out of curiosity and hiding my number and true IP.  Recording said Thanks for calling back.  If you'd like to be placed on our do-not-call list ....  Allow 48 hours to take effect.

In such  a situation the only button to press is  the Block button - no other.

answered call.  Something to do with medicare... I didn't allow the call to continue, opting instead to block the number & disconnect.