And the seller attempts to get you to

*take down the review
*amend the review
*berate you for the review
*tries to extort/blackmail you because of the review
 
Make sure you report this interaction to TER.
Don't tell the seller "oh ok I will take down the review", don't negotiate or even speak to them. Don't give in to terrorists demand. Give them a finger they will want the whole arm.  
Make sure you have proof of scheduling an appointment in case TER wants proof.  
 

If they claim the schedule doesn't line up and you reviewed the provider deliberately later so as you can be identified less easily - provide this info to TER. What's written in a review is more important than what month the sesh took place in as long as it's not too far out.  
 
Your reviews is what this site is built on.  

 
Thank you for your time and happy unbothered mongering.  
R