In the EU its easy - return it as unfit for the purpose for which it was sold - the firmware is buggy.

But above all and with all the UEFI secure boot sh*t - phone the company, email them make their tech support costs go up. Their margins are so low that if even a few of the people who can't get old Windows, Linux etc running on the box keeps phoning and complaining they'll make a loss on the product line.