Any producer of wheat, corn, grain sorghum, and oats against whom any assessment is made and deducted under authority of this article, if dissatisfied with said assessment, shall have the right to demand and receive from the treasurer of the certified association a refund of the amount of the assessment collected from such wheat, corn, grain sorghum, and oats producer, provided such demand for refund is made in writing within 30 days from the date on which such assessment was deducted from the sale price of wheat, corn, grain sorghum, and oats sold by such wheat, corn, grain sorghum, and oats producer; provided, that application for refunds of amounts deducted from the sale price of any wheat, corn, grain sorghum, and oats sold must give the name and address of the sale market or purchaser who bought the wheat, corn, grain sorghum, and oats, date of purchase, invoice or weight ticket number, if any, and the amount of wheat, corn, grain sorghum, and oats purchased from him for which the assessment was deducted. Within 30 days after the first quarterly receipt of funds from the Commissioner of Agriculture and Industries, and thereafter within 30 days after receipt of such application, the certified association shall, after such association determines that the assessment was paid as claimed in the application, refund the amount so paid as an assessment. The mailing by the association of a valid check in the amount of such assessment, payable to seller, within 30 days after receipt of the application for refund, shall constitute a compliance with this section.