Must be a cost-saving initiative in their support org. I've never seen a retailer that could even properly bucket losses into "our fuckup", "possibly our fuckup" and "satiating customer." And forget about always fixing things when they are recognized as a fuckup. There is too much incentive to not to do anything for the customer. Even when its the "right thing to do." Metrics often prioritize short term savings over burning a large-but-not-VIP customer.
I once worked with a retailer where even their Point of Sale voids were bucketed wrong. If a CSR were to accidentally scan the same $X item twice, they would void one on the POS. The stock control logic would keep the product in inventory counts, but the end-of-day financial tallies would look the same as if they manually applied a $X discount on an order.
I don't mean to imply Amazon is _that_ bad. But just because they're a big software employer, and AWS is a decent product, it doesn't mean that the support staff, internal software, etc... aren't shite.