(b) Any person or organization aggrieved with respect to any filing which is in effect may make written application to the commissioner for a hearing thereon: Provided, however, The insurer or rating organization that made the filing shall not be authorized to proceed under this subsection. Such application shall specify the grounds to be relied upon by the applicant. If the commissioner shall find that the application is made in good faith, that the applicant would be so aggrieved if his grounds are established, and that such grounds otherwise justify holding such a hearing, he shall, within thirty days after receipt of such application, hold a hearing upon not less than ten days written notice to the applicant and to every insurer and rating organization which made such filing. If, after such hearing, the commissioner finds that the filing or a part thereof does not meet the requirements of this act, he shall issue an order specifying in what respects he finds that such filing or a part thereof fails to meet the requirements of this act, and stating when, within a reasonable period thereafter, such filing or a part thereof shall be deemed no longer effective. Copies of said order shall be sent to the applicant and to every such insurer and rating organization. Said order shall not affect any contract or policy made or issued prior to the expiration of the period set forth in said order.