1. I am sorry to say that we are greatly inconvenienced by the fact that ~.
2. I am writing this letter to complain about ~.
3. I really must complain about the quality of the ~ I recently got from your company.
4. You seem to have supplied us with a product that falls far below the standard we expect.
5. The ~ I ordered from your store arrived broken. Obviously, no packing had been placed in the box before it was sent from the warehouse.
6. It is now over ~ since we made the above order with you, but the ~ we need badly now haven't arrived yet.
7. The product I purchased from you ~ proved to be quite a disappointment. Although it looks exactly the same as the one I saw in your commercial, it actually does not perform the same way.
8. As I have no interest in receiving a replacement, I am returning the product to you and demand that a full refund be made to me.
9. I'd appreciate it very much if you refund the money I have paid for it.
10. We would appreciate it if you would arrange for the replacement of the damaged items.
感谢信常用句式参考：
1. Let me tell you how much I liked / appreciated / enjoyed…
2. I want you to know how much we / I appreciate…
3. We appreciate your taking time to …
4. I don’t know how I would have managed without your help
5. I hope I can return the favor someday
6. Do let me know if I can ever return the favor
