[mothered]

So...... The UPS driver left the package at the front door (no sig required)  .  Perfect start for the SE.  Chatted with a rep.  Had to do a PR and they said to give it 2-3 days.  Shortly after a day I was given a refund.

Too easy, well done.

Now my question is this.  What if they were to require a signature.  How would I justify not receiving an item?

How would I justify not receiving an item?

You've answered your own question- you personally didn't receive your Item/package.  Anyone could've signed for It.

In other words, a package that's marked as delivered to Its correct destination, by no means concludes that you, or any member of the household, personally received/accepted It.