Cotton On Refused Discount On the Dress Without Any Clear Notice on the Website

I recently bought something from Cotton On’s website and was really annoyed by their confusing sale tactics. I saw the promotion for “2 for $40” on dresses, but when I tried to add them to my cart, one dress showed up at the regular price. I reached out to customer service, and they told me that one of the colors was marked as “Final Sale,” so it wasn’t eligible for the discount. But there was no mention of "Final Sale" on the product page or at checkout, and the returns section said “Free Returns.” After looking over their policy, it wasn't clear what it meant. When shopping for sale items, it's smart to be careful because there are some surprising rules that can make returning things tricky, and customer service might not be very helpful.