Work Dilemma- advice welcome!

So I worked at sonic for a carhop for a couple months. As a carhop you make below minimum wage so you get tips to add up to it. I ended up putting my two weeks in after there was a huge scheduling conflict. Well my GM didn't even allow me to finish out my two weeks, just automatically took me off the schedule. Anyways, the last day I worked I was filling out my tip sheet, and she had changed all my tips so that they were WAY more than what I had actually made!!! So I tried to change most of them back but I'm pretty sure I'll still be taxed extra for those tips. What can I do? Can I call corporate and report that? Is it even legal for her to change that?