【正确答案】[参考范文]
May 18, 2008
Dear Ms. Susan,
I am writing to you concerning a problem that has arisen from the purchase of your Del Laptop, model R55 on May 16, 2008 at ABC Store. I am disappointed because your product has not performed as it should.
To resolve the problem I would appreciated your refund or immediate repair service. Enclosed is a copy of the receipt.
I look forward to your resolution of this problem. I will wait for two weeks before seeking help from the consumer group. Please contact me at the phone number 010-12345678 at your earliest convenience.
Sincerely yours,
Nancy Reed

【答案解析】投诉信常用套语：
1．I regret to tell you that...
很抱歉告诉您……
2．I'm writing to you about (the shirt) I bought from you.
我给您写信是关于在您那儿买的(衬衣)的问题。
3．I am writing to complain of the bad quality of/the poor service of...
给您写信是向您投诉质量(或服务)问题。
4．I am sorry that I have to point out that...
很抱歉，但我不得不指出……
5．I was extremely upset to discover all this.
发现这个毛病令我非常恼火。
6．I choose to complain to you because I am sure you will be able to have the problem solved.
因为我坚信您能帮我解决问题，所以我写信向您投诉。
7．Sorry if I bring you any trouble, but I would like to make it clear that...
很抱歉给您带来了麻烦，但是我想把……问题澄清。
8．I'm looking forward to receiving your early reply soon.
期待着早日收到您的答复。