eBay listing my sales event items at 50% off despite me setting the discount at 20%?

I ran a sales event this week on some items, a 'Percentage off each item' of 20%. Looking at the sales I've made (including one just now), eBay has listed them at 50% off! I've taken a screenshot of the sale event.

Has this happened to anyone else? Should I ask eBay to refund the difference? I'll end up losing money on these sales. The event is due to end in a few hours.