I finished the Guardian Quest and I'm still warrior.

[Blutig Vernichtu]

I did the guardian quest killed the 25 gnolls killed the negotiator and tactician recieved the halberd but I am still a warrior not a guardian. What did I do wrong did I miss something? I am a lv 19 Barbarian and still a warrior.

[Eriny]

got to lvl up to 20 and u will auto change class to guardian.