PLEASE can anyone help? Would u QUIT?

Not long ago i was ually hared pretty severly by one of my bosses. I complained to head of company who fired him. Since this has happened, by other boss has been very rude, ignores me and refuses to speak with me and has dramatically reduced my shifts. I have spoke to head of company about this, and she denies it all. She tells me to move on with my life, forget anything has happened. I am also not allowed to tell other staff what happened. I am upset i am being trweated so poorly, i no longer enjoy my job and am suffering financially now. I am from australia. Does anyone have any advice?