Notwithstanding any other provisions of this chapter, any producer or importer who pays an assessment shall have the right to demand and receive from the Floraboard a refund of such assessment: , That such demand shall be made by such producer or importer in accordance with regulations and on a form and within a time period prescribed by the Floraboard and approved by the Secretary, but in no event more than sixty days after the end of the month in which the assessment was paid. Such refund shall be made not later than sixty days after submission of proof satisfactory to the Floraboard that the producer or importer paid the assessment for which refund is sought.Provided