What do you think of me being pissed off with my boss for going back on a promise
I think that is quite understandable. Why did your boss break his promise?
He's just very unpredictable and treats me like shit.
Having an unpredictable boss must be tough and you have every right to be irritated. Is it possible to submit a complaint about him to someone above him?
Nah, that won't do shit. You can't trust people who can lie. I have now decided to quit.
Ouch, that does sound very difficult to deal with then. Your boss going back on his promise sounds really horrible. Maybe quitting is best since you are not happy and you deserve to be happy at work.