The essay was completed, because you harassed me and threatened me, I chose not to continue business with you.
Point taken. However, a professional in this business knows that a work cancellation comes with a complete refund. That is the standard for writer initiated cancellations, which you failed to comply with. I am not saying the student did right by "slandering" you. I am saying that you dealt with him in bad faith so he cannot be blamed for bad mouthing you. Whatever the results of his venting on your business, let's just say you asked for it through your negative reaction to his email.