What if the hotel checks out at two o'clock and then at four o'clock?

Generally speaking, check-in before 1: 00 or 2: 00 in the morning is the room rate for one day until 12 or 2: 00 in the afternoon! You checked in at four o'clock in the morning, so check out at noon 12 or 2 o'clock in the afternoon. The hotel can only charge you half a day's room rate. Unless they overcharged you. Otherwise, this kind of complaint is generally useless, and it can be resolved through consultation with the hotel at most.