Don’t beat yourself up. Not all room types are offered for discounts. People often have to change resorts or room types to take advantage of a discount. Many resorts only have 1 or 2 room types available, so it’s entirely possible your room type wasn’t offered for your specific dates. But keep checking, inventory changes all the time. It’s always possible to find different room types as guests change plans & management re-evaluates inventory. Lots of people change room types as different rooms pop up, right up to the evening before check in.