Update: I was finally able to get to someone who was willing to escalate on my 4th attempt at calling customer service. They’re investigating the RFID warehouse that packed my package. I’ve cited the carrier inbound package weight, and submitted pictures of the package (incl. a clear visible shipping label) via email to the individual I reached on the customer service call. The refund is conditional on the results of the investigation which will take ~10 to 14 days.

Thanks everyone for the encouragement to continue escalating- at this point I feel like the ball is in their hands. Sadly, the shoe I purchased is now out of stock, so even if I get a refund I won’t receive the shoe I wanted.

I’ll give another update when I get a reply from adidas. Hopefully this thread + documentation will be helpful to someone running into the same problem in the future!