An habitation without hot water doesn't qualify as liveable in first world countries. You should have disputed only on that, leave on the first day and ask for

An habitation without hot water doesn't qualify as liveable in first world countries. You should have disputed only on that, leave on the first day and ask for full refund. If possible and necessary, deny the charge on your card. I've been on both sides and seen all sort of claims. Disputes are always messy, AirBnb seem to read them and try to deliberate.