Well, I thought everything was resolved, but yesterday evening (Check in was scheduled for today, August 29) I received an email from the Hotel Del with my "revised reservation" adjusting my rate to $344. Since there's no way I'm paying that, and the cancellation window passed last week, it looks like I'll be doing a cc chargeback. Does anybody else see any other options?

Cancelling a reservation based on a mistake rate: understandable. Adjusting the rate within 24 hours of check in: not cool.