Sam knows that the way Fiona treats her in A Cinderella Story her isn't okay, but she has a seemingly sound reason for putting up with years of abuse: college money. She views Fiona as the only way she will be able to afford college, so she does whatever Fiona tells her to do. Hasn't she ever heard of scholarships? Sam is clearly pretty bright and would qualify for several that could help her pay for college. She could also apply for financial aid or, in the worst case scenario, do what countless other students do: take out student loans.
Sure, dealing with crushing student debt doesn't exactly make for a happily-ever-after ending, but dealing with Sallie Mae would be preferable to dealing with Fiona and her abusive and manipulative tactics. Sam could also get a job to help pay for some of her college costs — something she already has plenty of practice at, thanks to all the time she spent working for Fiona.
