this is kind of a repost. i`ve seen it over in the scam section however (i wonder why?).
if they ask you to delete the item by yourself, you can go and delete some other epic of the same slot and hope the gm doesn`t pay attention. like buying a ring for heroic badges and delete a ring from kara... they sometimes don`t notice. bit harder with the arena stuff because of the names. worked for me once. my priest got s2 damage and heal gauntlets for the price of one like that. deleted the s1 heal gauntlets for it.
if they notice you deleted the wrong item, just tell them: OMGZ I WANT IT BACK! NEED IT! and they won`t accuse you of anything.
goodluck.