I recently had a similar review removed. Try this:
-Reach out via Twitter AirBnB Help "I have received a review that violates AirBnB Content Policy and need assistance"
-They will send you a PM asking for your account information
-Respond with your account information and add booking ####### has a review that "does not represent the author’s personal experience or that of their travel companions" as per AirBnB content policy." Because they never entered the home, please have your Content Policy team review and remove.
-You will get a personal call or message via AirBnB to work it out. Just keep saying the same thing "this violates AirBnB Content Policy, please have it removed".
-Don't discuss or agree to a refund (it has nothing to do with a review), the room was ready, you paid fo services to accommodate them.