@Stacey268 Yes, there are definitely cases where the guest arrives to find a property not as advertised, dirty, or otherwise unacceptable. Cancelling right away and applying for a refund, which you did is the correct way to handle it. And I think in such a circumstance, a guest should be able to leave a review to warn other prospective guests, and it's a good idea to do so.
But offering to not leave a review, or to leave good one in exchange for a refund, is considered to be extortion, no matter what.