These people had no relationship with you, so in fact they considered your gite as a commercial venture. They had no consideration for you since they did not understand any was due.
Sleeping on a sofa is not a crime. They probably had no idea it was not allowed. They considered their stay their as an arrangement made for them by their friend.
Let it go now, and look forward to the New Year.
Your friend's only crime is poor communication. Forgive them.
Go forward now, and do not allow a misunderstanding like this to continue to gnaw. No good could come of it.
Rest easy, and be happy in the new year.
Your good deed was not recognised, but good deeds often are not.
Give and expect nought in return.
Otherwise give nought.