Dear {Recipient},
Thank you for reaching out to us. I am very sorry to hear that the {item} you received was defective.
We take pride in the quality of our products, with each item undergoing several stages of quality checks before being shipped. Unfortunately, it seems that a defective item slipped through the cracks and ended up in your hands. We understand your disappointment and will be shipping out a replacement immediately.
Please expect the new {item} to arrive within {number of} days. You'll also find a return label in the {parcel/envelope}. May I request you to kindly attach it to the original packaging of the defective product and mail it back to us. No postage is needed.
If you have any further questions, simply reply to this email. Thank you.
Warm regards,
{Your Name}