You can't necessarily do anything, except as set out in 3), below:1) Unless you had a contract guarantying you the right to certain job protections (e.g. a hearing, or warnings before termination, or proof of infractions, etc.), the employer may terminate you at will, including for unproven allegations of roughness.2) You don't have a right to challenge or change what is written up in the personnel file--that file is company property, not yours.3) What you can do, however, is if the employer tells others that you were too rough with a patient (e.g. discloses that to prospective employer seeking a recommendation), that could be defamation, since it is a negative factual statement about you, one which can damage your reputation, which you believe to be untrue. (Untrue facts are defamation; true facts or opinions--e.g. "John/Jane Doe is a bad employee," is someone's opinion, not a fact--are not defamation.) If the now-former empoloyer makes a defamatory statement about you to others, you could possibly sue them for defamation and recover compensation. You would speak to a personal injury attorney about this.