The online store offers refunds for digital download within 14 days. For physical merchandise, you can seek refunds for orders that are not received, or anything that is deemed damaged or defective. Depending on the refund request, you may issue a full or partial refund. Refunds are issued by contacting Rockstar Games Support, while exchanges (wrong size or color of a shirt, for example) are managed through  Rockstar Games Supp.