Mo. Rev. Stat. § 149.031

The director shall make a refund or exchange new stamps for any stamps which are damaged, or for stamps which have been affixed to packages of cigarettes returned to factories, sold or shipped into another state for sale or use there or have become unfit for use and consumption or unsalable. Application to the director for the exchange * or refund must be accompanied by affidavit, damaged stamps, bill of lading covering shipment to factories or other states, or any other proof as required by the director.