To start off, I'm working on completing the MMXX title/seal and saw the triumph "Above and Beyond", requiring you to earn glow on a piece of armor. I thought that purchasing the ornament from Eververse after I upgraded my Solstice armor to Majestic would count for that. Total shocker, it doesn't. Was it dumb of me to think that? Yes, it was and I won't deny it. But this year's Solstice is my first, and I have plenty of room for mistakes.
Is there a way I can get the Solstice ornament set removed from my inventory/account and my 1.5k silver back?
Unfortunately, once you open the package, you can't return it.
As for the Triumph, you'll need to complete one of the masterwork objectives. The easiest one is probably the Nightmare Hunt as you can do one on the lowest difficulty.