As long as the goods remain intact and conform to the relevant return regulations, (underwear belongs to personal hygiene products and cannot be returned.

Article 24 of the Law on the Protection of Consumers' Rights and Interests stipulates that if the goods or services provided by operators do not meet the quality requirements, consumers can return them according to the provisions of the state and the agreement of the parties concerned, or require the operators to fulfill the obligations of replacement and repair. If there is no state regulation and agreement between the parties, consumers can return the goods within seven days from the date of receipt. After seven days, consumers can return the goods in time if they meet the statutory conditions for terminating the contract. If it does not meet the statutory conditions for terminating the contract, it may require the operator to fulfill the obligations of replacement and repair.