This this a clear cut case and amazon should process the refund, however, in general refunding is a hard problem for Amazon to solve due to the sheer volume fraud that occurs. For anyone unaware, go to telegram and do a public search for 'refunding'. There are hundreds of channels where you can pay someone to refund >£10,000 of stuff for you for a 10% fee. Afaik, the main method that 'refunders' use to defraud amazon…
For returns you have to print a barcode and put it in the box. You don't get your refund until they physically scan the code in the box. Maybe it's not standard everywhere, but this process has been around for some years now. If the package never gets to the return center, no refund would be processed…
This is also true for Amazon business purchases. I have returned items around $600 and have never been asked to put a code in the box.
But I’ve never returned anything over $1,000.