That's not how it works behind the scenes.

Vendors can drop prices and then do refunds in various ways (be it discounting prices on next shipment to let retailer recover the difference, cashback, credit etc.). Big retailers like ocuk have loads of ways to drop the pricing mid sales and get the monies back from vendors one way or another. As long as AMD decides that's how it should be, they can make it happen. This is exactly why the price in retail isn't set yet in stone and AMD is still debating what it should be, because they can make such adjustments with will propagate through retail very quickly.