OK, I guess there's nothing to be done from the Paizo side of things. Can anyone tell me for sure what carrier was used to deliver my package so I can contact them directly and ask that they not bend packages labelled "DO NOT BEND"?
Your shipping method should be listed on your My Subscriptions page (assuming you're talking about your subscription shipment; otherwise, I think it's in your order details). If you're in the US and it's in an envelope, it's probably USPS. I believe all Paizo shipments through UPS come in a box. Unfortunately, unless you have a punctilious mail carrier (which, apparently, you don't), the postal service as an entity doesn't much care about the condition your mail arrives in unless the shipment is insured (which Paizo's aren't). Which is a main reason many of us have switched to UPS: box = better protection for contents; trackable shipments; and insurance up to $100 included.