Email correspondence practice

Dear Mr. Na,

I appologize for your trouble.

On receiving your email, we checked the product, but it passed our test successfully. So we need to check the product that you received. Would you send it back?

If it had any inherent defects or was damaged in delivery, we can repair and send it back or can send you a new item. If not, you have to pay additional cost for repair or replacement.

I am looking forward to your response.

Best regards,

Yamamoto
Sales Representative
Best Nozzle, Inc.

Dear kangwonsu, I think your letter should be changed in some words as of the BIG CAPITAL.

Dear, Mr. Yamamoto.
We are appreciated your exact shipping the nozzle. Last Sunday we got that nozzle, we tested that on last Monday. Unfortunately, we found some defEcts under the surface. Actually, We cannot use that for our productS. Was there any problem when you sent that TO us?

We are appreciated WHETHER you HAVE ANY CLARIFICATION. ALSO, we would like you to replace THE DEFECT nozzle as soon as possible. ANY OTHER SOLUTIONS ARE WELCOMED.

Thank you.