Alchemy mastery problem

Hi there,
Playing on Lordaeron x1 Alliance
Level 79 warrior
Took Alchemy mastery quest for Elixir. Turned it in at Shatt and got Dungeon quest i cant even do - missing some quest -.-
Abandoned quest. Read guide - spent 800g on x4 Primal Might to do transmutation quest - went back to hellfire and i cant take new Mastery quest anymore?

wtf am i to do now?

Finish your Elixir mastery quests, once done, then you can change your profession mastery.