You made several incorrect statements:
We told you that we would call you after we completed everything at the airport, which you okayed. We did so, and then arrived at the apartment about half an hour later.
I lived in the US for 18 years, and my English is not so bad.
When you showed us the apartment in the afternoon, some of us already noticed the smell and complained. At 11 pm we called to say that we could not stay in the apartment, had made arrangements to move to a hotel from the following day, and would leave in the morning, leaving the key where you said to put it. You said you would talk to airbnb during the next day regarding a refund, and that we should call you again, which we did in the evening.
The street, in fact, was quite noisy, and there are a number of other things which were bothersome about the apartment, but none of this had anything to do with our leaving.
Please note that the smell which we found objectionable, the musty odor, is an indication of mold, which is a health hazard. This needs to be fixed.