How can I get a refund without deducting money from the ticket of the US Mission?

How to refund the ticket of the US Mission without deducting money, and how to refund it will deduct money. Under normal circumstances, the refund fee before the scheduled departure time of the flight does not exceed10% of the ticket price; If the ticket is refunded within 24 hours or 2 hours ago, a refund fee of 10% of the passenger fare will be charged; If the ticket is refunded within 2 hours, a refund fee of 20% of the passenger fare will be charged.