@Simona554 There's certainly no valid excuse for a host to accept guests to a dirty house. Cleanliness is the least a guest should be able to expect.
You don't say what the "issue" was with the toilet, but I can tell you that it is quite normal in some places for toilet paper to be put into a pail or wastebasket, rather than flushed. There are many countries where this is standard practice, as the plumbing infrastructure isn't capable of handling toilet paper, and it isn't considered to be an "issue" at all, it's just the way things are done. A host in those places wouldn't think to mention it in the listing, as it's just something normal where they live that everyone does. Also, even in countries where this isn't standard practice, some remote or rural homes which are on a private septic system don't want people to flush toilet paper, as it can damage the system.
If this was the case, then you really have no cause for complaint about simply being asked to put the tp in a pail. But a dirty place is a cause for complaint and the host should have come right over or sent someone to clean it properly.
And protocol for Airbnb guests (this is stated by Airbnb in their information for guests) is to first notify the host if you arrive and find a unacceptable situation, to give the host an opportunity to address it. Sometimes things can happen that the host might not know, like the cleaning person was supposed to show up to clean that morning, but didn't, and the host isn't even aware of it. Or maybe the stove stopped working when the last guests were there, but they ever bothered to let the host know because they weren't really into cooking anyway and just went out to eat instead.
Perhaps the host might have sent someone to clean if you had done that, rather than cancelling immediately. If the host is unresponsive, or rude, or says they can't or won't do anything to correct a problem, then you call Airbnb and cancel. Had you done it that way, which it seems you didn't, you might have been more likely to have Airbnb grant you a refund.