Assuming the buyer didn’t enter the wrong address, which seems a good assumption, pretty clear he’s entitled to a refund from seller. Ultimately, this seems to be AG’s fault, but in all fairness, and I also think in law, that should be worked out between seller and AG,
as the facts are explained, buyer had a right to delivery of the goods, and is the only party of the three involved that could have done nothing to make sure this didn’t happen. Not saying the seller is ultimately the one who should bear the loss, but between seller and buyer the buyer is entitled to a refund leaving seller with a claim against AG at least that’s what my 40 years of practicing law tells me