This is devolving into a very public display of knife twisting by otherwise grown men who should know better.
After all, they are just off-the-shelf, commodity amplifier modules being screwed into cases, all around the world by every man and his dog, with or without a bit of customization. The variations in fit and finish will be enormous and range from the unsafe to perfectly serviceable.
People don't want to pay for an NAD (or someone else that uses Hypex/Purifi in their gear) with production line quality, backup, service and parts, but want to pretend they are getting SOTA performance in a cheap box for way less money.
Sorry, I have zero sympathy. It's nothing more than a kit build done poorly. You (the OP) had the opportunity to remedy the situation with a refund and move on, but wanted to make a scene about it all.