
If you didn't actually use the paper they provided, there are probably no immediate academic consequences to you even if they do contact your professor.
Unlike criminal law, where the mere
attempt to commit some crimes is an offense in and of itself, there's no such thing as "attempted" academic dishonesty if you didn't actually submit someone else's work for credit, even if you purchased an essay with that intention, originally.
If they're not actually extorting you for more money and/or you did use any part of their work, your smartest move to avoid having to deal with the accusation would probably be to just cut your losses and remove the bad review.
This might be your smartest move either way, because whether or not their reporting you has any immediate
academic consequences, they could still simply publish all of your emails and the essay together with your name and email.
If they do that, any future prospective employer who Googles your name will find that, and unlike your school, they probably
would consider that and avoid hiring you because of it, especially since they don't have to disclose to you why they didn't hire you.
If they do extort you for more money, you should contact law enforcement wherever the company is located, which, unfortunately, could be a waste of time depending on where they are, if they're outside of the U.S.