英语投诉信怎么写？

Hello,

I am your customer. On [当时邮购的日子], I ordered a shirt from you [或者填上那个公司的名字]. The item was
delivered on [物品寄出的日子]. On [发现问题的日子], I discovered that item was faulty. The size of the shirt does NOT match the size that I chose originally. Under law, I now request to have the correct item mailed to my address:[你的邮寄地址]  . Please response to this lettter within [要求卖家在多少天内回信] days from receipt .(为了方便卖家联络你，你可以加上这句话 I can be reached at [你的电话号码].)

Sincerely,

你的名字

日期

以上供你参考，希望能帮得上你的忙。 Good Luck.