Below is an example to work from when addressing price adjustments after a sale has started
Hello Matthew,
When we put items on flash sale to clear a final few items at end of season, we do price adjustments for folks who purchased within the previous 48 hours, on a discretionary basis. Your order was placed on August 11, which was 11 days before the sale started. Since your purchase was well outside the time window, we are unable to make the adjustment you have requested.
We only had three pairs of quad shorts left when the sale started, none in your size, so they would not have been available at the sale price. The sale is a clearance of leftovers in odd sizes/colors.
We thank you for your understanding,
The Team at Full Kit Gear