As you well said you never read the house rules and it is hard to believe you didn't read them when you have used airbnb so many times and reading your past reviews you mention several times the house rules of the places you have been. Let's be straight with the story. You arrive not 10 minutes later but 50 minutes. You came and try to play around the policy from the beginning making up lies that had no sense, specially when it is simple, if you arrive late you have to pay the late check in fee. For the same reason if you check out at at 5 am we have to come close the apartment.
Airbnb told you that you had to as well.
You FORGOT to mention the discount we offered you to book the apartment because you explained it was a very special trip with your mom and we did offer you a discount because we are FRIENDLY and flexible, more than 100EURO.
If it really wasn't an excellent experience it is because you didn't want it to be because if you check all the reviews for the apartment, always with the same policies the result is excellent. We love what we do and be part of our guests experience.