I have exactly the same problem. Created an in-game ticket, the GM told me he couldn’t help me. I deleted my Cahce, Interface, and WTF folders. Re-loaded the game. Headed west of the Teerakai town to The Eternal Kurgans /way 37.0, 67.0, the quest giver finally spawned. After completing the quest yet a second time I am STILL unable to turn the quest in.
This is one of two quests that I am completely bugged on for two separate Sourjer achievements, both of which are required for Loremaster of the Dragon Isles. The other quest being Refti Retribution which has its own bug forum here: