I don't know what was said, and I'm not trying to argue with you. There are limits and laws that define what you can and can't say and do under the Freedom of Speech. I'd suggest looking into it. But I don't think your harsh review has anything to do with freedom of speech or legal issues. It's a very common phenomenon for people to write vicious comments and for business reply to them without taking any legal stances. You wrote a harsh review, and now they are giving you the opportunity to explain what happened and how you'd like it resolved. There's a very small chance this will be taken into court, so I wouldn't worry about legal issues.