I appreciate how frustrating it is when a guest misreprents your property.
Perhaps it's worth asking a friend/s to read through your listing to see how it comes across, particularly so guests are clear as to the set up. So if they are renting a room in a house that is normally lived in by others, but they have the place to themselves then say that.
When you/your cleaner prepares your home for your guests do make sure going forward the temperature is set to take into account the weather at the time.
. Next time draft your review and wait a day or so before posting it to give yourself time to think it through. Perhaps a less defensive review might have been something like...
" We want all our guests to have a lovely time in our home. I did mention when I showed you around (or however you introduce guests to your place) to let me know of any issues and would have been happy to help with any concerns.
Our guests always have the place to themselves thoughout their stay, as happened when you stayed.
The room we make available to our guests is a sunny well aired room and having checked it before you came and after you left we couldn't find any signs of mildew.
The Metro is within a 15 minute walk".
By the way I notice this is the second guest to flag issues with high temperatures in the room, so when you/your cleaner prepares the room do double check on the temperature and turn it down if a previous guest has turned it up. Also make sure it's clearly highlighted in the guide book you leave for your guests about how they can alter it.