Got a warning email from cis@amazon.com

How is it known if the failure is theirs?
All that’s known is that the OP claims the package was not received.

But YES - Amazon needs to change their policies such that some form of delivery confirmation can be required.

No confirmation of delivery - reship
Confirmation of delivery - shit outta luck on replacement.

If this really so difficult?

And to Grude - I would have told the guy to go pound sand, if I have confirmation of delivery the buyer can follow up with the delivery company.