If the customer wants to return or exchange the goods, if agreed, the customer service staff should give instructions on how to return or exchange the goods in the email and provide the return address. Of course, it is important to remind the customer that the returned goods cannot affect the secondary sales. The customer service staff can add a sentence “Returned goods must remain intact and in perfect condition” in the letter to protect the rights and interests of the seller. You can refer to the following sample reply. Best regards!