Any producer against whom an assessment is made and deducted from the proceeds of sale, if dissatisfied with the assessment, has the right to demand and receive from the treasurer of the Council a refund of the total amount of assessment collected from the producer if the demand is made in writing to the Council within thirty days of the date the assessment was deducted from the sale proceeds. The demand for refund must contain the name and address of the producer, the date of purchase, the number of head sold, the amount of the assessment, the name and address of the collecting agent, the date of sale and the invoice number. The refund is made upon determination that the assessment was paid by the producer.