Are A to Z's getting harder to appeal?

Just wanted to survey some sellers on their experiences with A to Z's lately.

We have lost two appeals recently which amount to over $3000. They both were sent via the LTL carrier TForce, and we have signed delivery receipts from the customer.

Amazon ignores that as POD, and because these are "large and heavy" items they are not eligible for the buy-shipping program.

Any comments? Advice?

The other issue is we have been getting way more UPS returns that are just empty envelopes. They are followed by demanding messages to "REFUND ME NOW, I HAVE SEEN IT IS DELIVERED!"