Lost ALL reputation with The Oracles

I was finishing their quest chain and the last quest seems to be bugged, i have to kill a boss and he became immune and i could not end the quest. But i was ok with not finishing it, but then i realised that my exalted reputation with The Oracles was now honored and all the equip that i bought from them dissapeared..

I lost a lot of time and equipment, i really wanna know if it was my foult somehow, or if its bugged. Also how can i regain my rep or if i'm doomed

Thanks in advance

(I play in Ragnaros, my character name is Strained)

That quest is for switching between Oracles and Frenzyheart Tribe. You can go back to the cave later and switch back but you will not be exalted. There are 2 quest givers. 1 for Oracles and 1 for Frenzyheart Tribe.