This number called my cell phone and when I tried to call it back, it said it was no longer in service.  It must be a scam.

Spoofed caller id. That usually spells SCAMMER. Also it's not a good idea to call scam numbers back. It can result in more calls. Just block when you get calls like this.

Call to personal cell.  Caller ID said Palo Alto, CA.  Didn't answer and no message left.

Called said name was Michael and that my vehicles warranty is about to expire.  No company name, automated message asking for me to press a number to continue.

I recently got 2 calls that hung up right away the other day and 3 calls all from 3 different numbers this morning. I keep blocking all unknown numbers I see after googling and yet it seemed they continued to call with different numbers!! What should I do? I believe I'm on the "Do Not Call List" since way back then.. This is very very annoying, and thats why my phone is most of the time on Silent nowadays!!

Here are these certain numbers I've mentioned:
3852637017
8316122246
6503007994
3852183057
If you see these, stay away and no need to pick up!