Epic chest in spellplagued dungeon wouldnt open!

Last night, after a long and hard fought battle, we beat the final boss in this dungeon. However, the chest didnt make the familiar ringing sound, nor was light pulsing out of it like it normally would at this point. Just to be sure, I verified I had two epic dungeon keys, and one daily dungeon key. The chest still would not open for me, so I tried leaving and coming back, but that didnt work either. At this point i was up for almost an hour past my bedtime and gave up. Please tell me there is a way to get the item i earned and that last nights foray wasnt a waste of time because of some glitch?