拒絕索賠有很多種原因，我們來看看一些常見原因的表達。

1. On going into the matter you mentioned we find that the poor performance of the engine is due to your incorrect use of a different motor oil.
我們對你方提到的事情調查后發現，發動機故障是因為你們誤用了不同的機油。

2. Items like this are not to be returned once they are accepted by purchasers. We have established this regulation for offering our customers the definite best quality products.
此類商品一旦售出就不能退換。我們立此規定是為了向顧客提供絕對上等的產品。

3. This is exactly the first complaint from our customers, from which we can understand you have met much inconvenience in satisfying your users.
這確實是我們收到的第一封索賠信，我們可以理解您在滿足用戶需求方面的許多不便。

4. All the items for export must be under the tight seal which ensures that we always put the Total Quality Control into execution.
所有出口品種都必須真空密封，以保證全面控制質量這一措施的實行。

5. Our investigation reveals that the articles we packed were identical with what were listed on our invoice. We are afraid that the cases you mentioned must have been unpacked during the transit. We are enclosing a copy of the invoice for your reference and suggest you make further inquiries at your end.
我方調查結果表明：我們打包的東西和發票上的一致。恐怕你說的那些箱子在運輸過程中被人打開過。隨函寄去一份發票復印件，建議你方進一步調查。

6. We are extremely sorry for the late delivery of your last order. It is due to your delayed opening of the relative letter of credit.
非常抱歉上一批貨交晚了。因為你們的信用證開得太遲。

7. As stipulated in the contract, a minor discrepancy in colors is permissible. That is why the case you brought up is still under a normal practice.
如合同所示，顏色上的輕微差異是允許的。故此，你提出的情況依然屬于正常做法。

（例句來源：《國際商務寫作教程》，對外經濟貿易大學出版社 英語點津 Annabel 編輯）