How to write a letter for Defective Products

Client complaint about product :

Dear sir,

Many of our customers have been complaining about your roller-ball pens. They are not giving clear satisfaction, and we have had to refund the purchase price on many of them. Pens received before were satisfactory and we had no complaints from our customers.

Please check if there were an error in the making of these pens. We also suggest you to check if they are being packed with sufficient protection.

Yours very truly,
(your name)

How to create a letter for Defective products

How to write a letter for Defective products :

Dear sir,

I had bought the XXX Baking Product, order no:1111 on 2nd November. I received today a package in response to my order for the set of leather-bound luggage advertised by you in the last Sunday's times. As soon as I opened the package, I noticed that luggage had been seriously damaged.

Could you please have a look and see that this case would be picked up and replaced? If a duplicate case is not available, please arrange to have the entire set picked up back and the cost credited to my account. I am enclosing a copy of the receipt to help you initiate immediate action.

Very truly yours,
(your name)