you could complain to higher but in the real world a senior management isnt really gonna listen to a new employer over one of the managers. All your other coworkers that will act like they will back you up will suddenly fall silent and leave you hanging big time. It isnt working just give notice and move on, most likely they will cut your hours to basically nothing , but that is ok, you gave them two weeks notice, if they fire you or tell you to leave that day, its there problem. You did the right thing. Look at what is best for you in the long run. Telling them off, or quitting and storming off will make you feel good for a few minutes, but they really wont care. And it could bite you in the butt down the road.
Be professional , short and sweet. I intend to leave in 2 weeks. all you gotta do.