Originally Posted by
Twickenham
I'm not entirely sure, but I think that you must submit the form at least 24 hours before your reservation. I would still call and ask - the worst they can say is no, and you can just cancel and reserve at the cheaper rate.
That's exactly the response I received - "Sorry, you didn't submit 24 hours in advance" so we're denying your claim. The claim was actually valid but not prior to 24 hours of the reservation.

I sort of thought they'd do that but was hoping they'd honor the claim. I guess it gives Marriott an easy way out for paying any of these claims if the rate actually decreases the day of the reservation.
I already have the second reservation made so I'll just cancel the first. As someone previously mentioned, it can't hurt to ask.