arbiter set with AP

hello i saw that in katalan we can have the arbiter set (Armor and weapon) with abyss point but don't work :crying:
when i want buy an item to the npc a have the number of AP needed for the item selected, i click on it to buy it and i have the message who say to me that the AP will down and ask me if i want buy. I clik on yes and the item desapear from the selection but my AP don't downgrad and the item isn't in my inventory :andy:
is it a bug or just don't work
tks to fix it :wink:

 

Arbiter items are not available in game and can only be purchased from the cash shop. NPCs selling those items are intentionally disabled.