The US Mission is booked! The next day, the US delegation was closed, so I went to the front desk to renew my fee. What if the price is different?

I suggest you contact the Consumers Association for handling. The hotel's solution is unreasonable and should be based on the price you set. Because consumers book in the process of price change, both merchants and Meituan APP are responsible, but for consumers, they are victims, so consumers can stay at the original price. You can ask the Consumers Association to intervene.