I was in O,Reilly auto parts last week ago and was called a thief by a employee.

You may have a claim against the store for defamation of character. A false statement was made and was presumably published to a third-party, and that constitutes slander per se, which means you do not have to prove damages. When any plaintiff files a lawsuit against a defendant for defamation, they have to prove that they have been damaged. However 'slander per se' allows a plaintiff to recover damages without the need of proving same, if the statement falls into either of four categories. 1. Youve been accused of having a loathsome disease 2. You have been accused of a crime, 3. You have been accused of being a person of ill repute, or 4. You have been accused of being dishonest in their business dealings. Finally, there should be a source of recovery because 99% of the time commercial businesses like this have insurance policies that cover advertising injuries. That is a fancy word that means that defamation is an insurable risk that commercial enterprises protect themselves against. So what you should do is to retain counsel to represent you, and have a claim filed against the business. If they refuse to negotiate with you or you do not have any luck in finding a lawyer to represent you, you can always file a lawsuit against the business in small claims court.