Help! My two year old is out of control!?

First off let me say I'm not a push over, she gets told right and wrong and gets time outs and things taken away from her when she misbehaves. But this doesn't seem to deter her bad behavior. Like lately she will cry for something and then when I go to give it to her she screams she doesn't want it and then I go to put it back and she screams even louder. She will keep this up until she gets distracted, usually by her father. She also physically fights me sometimes when I try to put her to bed. Can anyone give me any good tips on why she's doing this and how to get her to behave? I understand two year old's test their boundaries, but knowing other parents with two year olds I am certain this behavior is not normal (at least to this extreme). Oh, and I will not hit my child so please don't suggest as a remedy. Thank you!