The Battle For The Undercity....

I am currently trying to complete this quest, but it seems Thrall and Lady sylvanas are stuck battling over the Royal quarter. When i first got there I thought I could join them in the fight already in progress but soon figured this wasnt going to happen. I found them fighting but couldnt see what they were attacking so attempted to go back outside and wait, but the elevator is out (DOH!!) So I hearthed to Dalaran and ported to Org and made my way back to UC. My hearth is far past its cool down and they are still battling over the Royal Quarter. Please any help is greatly appreciated.

I do have an open ticket and Posted this in the bugs forum. It was recomended that I might be able to get help posting here. Thanks in advance for your help