When I booked a hotel, I said I would stay for one day, paid for one night and left the next day without checking out. After two days, the hotel asked me to pay two more days.

It shouldn't be! This is entirely the hotel's own reason. When you checked in that day, you agreed to stay for only one day. For the hotel, he will call you when you check out the next day in advance to confirm whether to stay. If there is no contact information, your deposit is not enough, and there is no luggage in the room, don't stay in this room, and the front desk will check out automatically in the system.

Therefore, you have every reason to refuse to pay for the next two days. Just tell him you only booked it for one day.