The hotel overcharged the room.

What card do you use? If it's American Express, they won't receive your money unless you sign it. But according to the experience of booking, they only charge the pre-authorization of your credit card as the deposit for booking. Only when you check in at the hotel can you sign the card paper and make a real deduction. To be honest, if you didn't check in at that time, this refund is a problem that can be studied. Under normal circumstances, hotels don't want to return, but there are many loopholes in domestic bank cards. It is still possible to recover after communicating with the hotel, but it is best to check in as scheduled.