考研英语作文中，投诉信是一种常见的题型，需要考生能够清晰、礼貌地表达不满和期望。以下是考研英语投诉信万能模板，供您参考：

模板1：

Dear Manager,

Last week I bought ______ at your store and when I got it home it did not work at all. When I tried to return it to the store, I was told that I could not get refunded.

The sign in your store says that money is returned within 7 days of purchase if any problem exists, and I did that within the said time. Thus I insist that I should have my money back by returning the ______ to your store. If I do not receive any satisfactory response, I will further complain to the Consumer Protection Association.

Yours,

Li Ming

模板2：

To Whom It May Concern,

I am writing to complain about the poor service of your ______ I received when ______.

The reasons for my dissatisfaction lie in three points as follows: 1) ______; 2) ______; 3) ______. Under these circumstances, I find it difficult to ______.

I am sure that you are able to thoroughly understand my discontent, which you are bound to replace with a satisfactory solution. I would be grateful if you could ______ as soon as possible.

Yours sincerely,

Li Ming