Vendor Won't buy back item

Hi,

I'm trying to get a refund from to any vendor for the Battlemater's Aggression, unfortunately for each vendor nothing happens and when i try to manually try to drag and drop it in the buy back menu it says "the merchant doesn't want that item". I don't understand why it's doing that because I still have 45 minutes left on the timer, and this is not a stackable item or an achievement, so why won't it let me refund it? Thanks...