Centaur Blackmail

''Speak with the Centaur in the Command Post''
Ive completed every quest and mission I can find but still no centaur in the command post. Any suggestions as untill I do this quest im not going anywhere.
Thanks Mad mouse have been out there but noshow on the cenaur I know where he is ment to be and unlocked quest on 5 other characters but he wont appear for my Sin

Remember that the Command Post referred to is out the north exit of the Sunspear Sanctuary, turn right and he should be a bit in front of you, under one of the tents.

hope this helped.

Is the quest marker on the radar visible in the Command Post? If not then just abandon the quest and get it again from Lonai.