如果你需要投诉旅行社，是一些英语表达，可以帮助你有效地表达你的不满和要求：
表达不满：
- I am writing to express my dissatisfaction with the service provided by your travel agency.
- I am extremely disappointed with the way my recent trip was handled.
- I regret to inform you that the tour organized by your company did not meet my expectations.
具体问题：
- The accommodations provided were below the standard promised.
- The tour guide was unprofessional and lacked knowledge about the destinations we visited.
- There were significant delays and changes to the itinerary without prior notice.
要求补救措施：
- I would like a full refund for the tour as it did not meet the advertised standards.
- Please provide compensation for the inconvenience and disappointment caused by the poor service.
- I expect a formal apology from your company for the mismanagement of the tour.
结束语：
在结束信函时，可以表达得到尽快回复和解决问题的期望：
Thank you for your attention to this matter. I look forward to a prompt resolution to this issue.
表达可以帮助你有效地向旅行社提出投诉，并得到合理的解决方案。