Any written or oral contract for the sale of milk under an unfair trade practice shall be unenforceable by any dealer participating therein. Any dealer who fails to comply with any direction or regulation of the Commissioner of Agriculture issued hereunder shall have committed an unfair trade practice with respect to each transaction in violation thereof and each such unfair trade practice shall be a violation of this part. In any action against the license of such dealer, or in any other action to enforce such direction or to attempt to enforce a contract for the sale of milk in violation of such direction, the record of the unfair trade practice hearing or any relevant part thereof, the findings made and direction issued shall be admissible in evidence and thereby incorporated into the record of such action and shall be reviewable only as part thereof. Regulations issued under § 22-245 shall be reviewable only in the manner hereinafter provided respecting orders and regulations.