This is a legal document.
It relates to contract law, in terms of being correspondence concerning a dispute under the terms of the contract.
You are not accepting responsibility in this case, and you are stating you're not at fault in terms of your obligations under your contract.
Any statement you make must make your position clear, and give reasons for your denial of responsibility.
Make an offer of mediation or further discussion if you consider it appropriate.
Any dispute under contract can be time consuming and expensive for both parties. Do NOT make any commitment to any action under the contract until you're sure of your facts.
Re: Claim of supply of defective goods / materials
I refer to your letter / email of (date) concerning your claim of defective / damaged / unsalable goods delivered to you.
I regret to inform you that we can accept no responsibility for any defects in the goods. All materials shipped are inspected prior to packing and shipment, and certified as being of commercial standard prior to despatch.
Under the terms of (cite clause of contract) our contract of supply, you are entitled to (quote clause terms) dispute payment under these circumstances.
In view of the possible time frames and complexities of action under the terms of the contract, it is suggested that:
I can assure you that if we are satisfied that your claim is justified, we will immediately refill the order, and that no liability for the goods will be incurred by you.