You said the beta ran, but not the official release. I don't know what mileage you'll get out of that with Blizzard, but I would at least try to coax them into an actual refund, since you relied on your experience with the software. (It's more than reasonable to expect the official release to behave the same as the beta or better.) I don't know how much of a fight you're willing to put up here. You were sold something you can't use, and a prompt refund is what you should get.
Failing that, it's really a matter of preference. If you really like the game, and a fake refund (usable only at Blizzard) doesn't appeal to you, I guess waiting for a patch or hardware upgrade will have to do. Sucks, though.
Did some quick searching. (Google: destiny ii beta works official release crashes)
It’s a particularly strange issue considering that the problem wasn’t present in the PC beta, and you’d think a bug affecting an entire class of CPU wouldn’t be introduced in the transition from beta to full release.
https://www.pcgamesn.com/destiny-2/destiny-2-phenom-crashYeah, exactly. You acted in good-faith reliance on the beta. Maybe try to join forces with others who have been similarly screwed out there?
Edit: Thinking on this a bit more . . . If I was in on the coding of this, I'd be able to crank out a patch in an afternoon. I know that the beta works and release does not. Likely due to last-minute optimizations using more advanced instructions. I can insert both sets of code into the program, detect Phenom IIs at game launch, and set the appropriate code path. I can't imagine they won't patch this, given the uproar, and the relative simplicity of a fix. Then again, I don't know the corporate hang ups at Blizzard.