Derivative

Hello, I'm writing this in english so hopefully someone can read it. Anyways, I was on my paladin Derivatives on the instant lvl 90 pvp server and was doing the quest http://www.db.pandawow.me?quest=10630/beneath-thrallmar for the Underworld helm for transmog. Basically what happened was that I d/cd after i completed the quest and now I don't have the piece of transmog in my bags. Any help will be appreciated. Thanks, Derivative