Item restoration or chance to buy back the item

Hi, im making this post to see if by any chance i can get an item back.
Basically im looking for a way to get the "Shattrath Leggings" (quest item, bis for many mdps clases until swp) back, i have the item in my bags and for some reason they dissapear, im a pve raider and this item rn is super important for me, the thing is that i want to know if there is any way that i can get the item back, i know that in normal sv gms are willing to help with this and i hope here they can do the same.
AND if the answer is no im willing to pay a logical amount of coins to get the item back but for that i need the ppl that works in onyxia to put it in the store.

Disable your addons and make sure it's not there.