Yeah code seems to be finished. It now doesn't work on the stuff I had ordered yesterday with the discount.
The items are £25 & £22.40 full price before the discount that does not work. Maybe cos one of the items was allready reduced it would not take a further 20% off but I tried wirh the other top at £22.40 on its own and it still would not apply the discount when on the pay page.
Your items were originally £63 and £28 id guess if you just go look at their price on the page where you first clicked add to basket. Example: the united top in my photo in previous comment says £48 beside it but it's a £60 top.
It doesn't work on already reduced items is what I've found
Don't give up yet, what tops are you looking at?