@Igor55, this is very frustrating. Since I started hosting, I have learnt that there are some guests you can't please no matter how hard you try.
I recently had a couple who I knew were going to be problematic before they even arrived. It's a shame I didn't pick up this vibe before accepting the booking. However, I treated them with the same kindness and consideration I would for all my guests. I was super friendly and tried to make sure they had everything they needed. I tried to check up on them during their stay to make sure everything was okay, but they didn't respond.
From the moment they arrived, I suspected they would find something to complain about in their review - I just didn't know what! It was very annoying as they broke some important house rules, e.g. they smoked drugs on my property, but then made untrue criticisms or complained about things I could have easily sorted for them if they had bothered to communicate with me. Anyway, I had a rant on the forums about it and tried to move on because I am confident there was nothing more I could have done for them.
I know it is even more upsetting when you think a guest has been totally happy and then leaves a bad review/ratings, but we both mostly get five star ratings, so must be getting it right most of the time!