This really sucks. I’m sorry, i think Amazon didn’t handle this release well.
Regarding Amazon selling multiple copies to one customer, it was always like that, it’s getting old and tiresome to read about it.
If you think about it, Amazon is not only a retailer but also a Marketplace where those same people who bought multiples can resell later at a significantly higher price to customers who can afford it, and Amazon will get a nice cut from each sale. That way they make significantly more money from the same 2000 print run, compared to as if they sold the whole run to 2000 unique customers for the lowest retail price. I know it’s pennies for them when you think about this one release in particular, but at a huge scale they end up making way more money like that. And they’re not a small boutique company who cares about retaining each customer, they’re at the scale where they don’t care. They just want to sell as much stuff as possible, as quickly as possible. And selling 20 copies to one customer, minimizing any potential customer service support, sounds like the best way to achieve their goals.