OP here. Just an update.

I tried the twitter team, who passed me off to corporate accounting. They sent one email asking me for more info (that I had already given them), and then went silent. I've sent 5-10 emails over the past 2 months to the accounting department asking for an update or reply, and every single one has gone unanswered. It's been a really pathetic showing on their part, and honestly, surprising. At this point, I'm not even sure it's worth pursuing anymore.

Pretty disappointed with Hyatt. Too bad, as I've had only positive experiences over the past 10 years.