I've heard from establishments after leaving reviews on several occasions. Typically they will either offer a free meal or a refund of the unsuccessful meal. I will update a review to let people know that I was taken care of, but I haven't ever taken down a review. I would consider doing so if my experience had been one-off, and I understood that it would not happen again (e.g., if an employee acted terribly and was no longer working there).

One frustrating incident I had was when I stayed in an airbnb and found cockroaches, lack of hot water, and general filthiness. I wasn't able to leave a review because airbnb moved me to another unit (after many hours spent on the phone), and my account showed I had never stayed in the problematic unit. I can see why hosts would like a policy like this, but it's terrible for guests.