投诉是人们日常生活中受到欺骗或不合理、不公平的对待时的一种积极有效的应对方式，而写投诉信是人们无法直接陈述或不便于直接陈述时所采取的必要手段。
投诉信通常是写给厂家、商店、消费者协会、报界或厂家、商店的上级主管部门，揭发产品质量的低劣、服务态度的糟糕，抱怨不应出现的情况或问题等，以求得解决的信件。
写投诉信要实事求是地把问题讲清楚，态度要冷静，要写得有理有据，令人信服。做到有礼貌，不能恶言伤人。
一、基本结构
1．在投诉信件的右上角写投诉人的地址。下一行靠左边写受诉人的地址。
2．接着靠左边写礼貌的称呼。
3．引出主题。说明投诉原因，给出具体的信息，包括产品名称、销售服务、在何时何地购买物品及物品出现的问题等。附上保证书和收据的复印件。
4．给出投诉要点。例如：
(1)为什么这一产品的广告有不合实际、错误引导消费者的嫌疑。
(2)产品有什么问题。
5．说明你的要求。如果没有满足你的要求，清楚地说明你想要进一步采取什么样的行动。
6．正式结尾(Formal ending)
投诉信的最常见结尾就是：I look forward to hearing from you.
7．署名(Signing off)
写完后应签名落款，写在结束语的正下方。
二、增分佳句
1．I am writing to tell you about ..., which I bought from ... on ...
2．I enclose copies of the guarantee and the receipt.
3．In your advertisement you claim that the watch is waterproof./The advertisement gave the impression that the jacket would last a lifetime.
4．However, the first time I went swimming, the watch stopped working./However, after only one wash, the colour had faded.
5．When I took the ... back to the shop, the assistant said it was my fault and I hadn't read the instructions carefully.
6．I would like you to refund my money.
7．Unless I receive a satisfactory reply, I will write to the Consumers' Association.
