Unable to refund a WF item

Hello,

Anyone help how to refund an item i bought just now? Refund works on my another character - for example few minutes ago I get refund for my shammy wrathfull item, but I cant get back my points for wrathfull retribution legs (no enchants or gems) - shows npc generic response „Sorry, unable to refund that item.“ . Already tried to disable all addons, delete cache, put those legs into main backpack, tried several vendors in dalaran but nothing works.

Thx for any advice