Quest glitch?

[Telestos]

I'm on one of my games quests (Act 10, South anchors away) and at the end of the quest I'm suppose to beat the boss WungSam. Please note I have restarted this quest about 6 times now.
After defeating WungSam the quest doesn't register that I beat him and I cannot continue on playing from that point. 
I have tried repairing files and nothing has worked.

Anytime I log on it restarts me at this quest.

 

Any idea on whats going wrong?