航空公司可非自愿地降低座位级别;乘客应提出退款要求的文件。 Airlines may involuntarily downgrade seats; passengers advised to document issues for refund claims.

由于超额预订、飞机变动或机组人员休息需要,飞机的非自愿座位降级。 Involuntary seat downgrades on flights occur due to overbooking, aircraft changes, or crew rest needs. Air Advisor的Anton Radchenko建议乘客用照片记录降级情况,并书面解释索赔。 Anton Radchenko, from AirAdvisor, advises passengers to document the downgrade with photos and written explanations to claim compensation. 退款可以通过具体的网上表格索回,但航空公司往往更愿意提供凭单。 Refunds can be claimed through specific online forms, though airlines often prefer to offer vouchers. 乘客应积极主动和坚定,确保任何退款的计算均以原订票价格而不是现行费率为基础。 Passengers should be proactive and firm, ensuring any refund calculation is based on the original booking price, not current rates.