Mod - I think Audiodeluxe reduced their prices during the day because some of the sales (like Waves) were officially for one day only and they were being undercut elsewhere. They couldn't wait till next week or even next day as it would all be over. I noticed a few things change during the day in various places. The best thing to do in that case is to contact them like you did. They are usually understanding.
On a side note, even if people missed the sales by a day it's still worth checking the relevant stores as many conveniently don't alter their prices for a day or two. Even if they have, you can still ask for the sale price.