No action shall be taken by the Insurance Commissioner under the provisions of section 3 of this act¹ except after a hearing held upon ten days' written notice to the party or parties concerned. Classifications of accounts and records or reports shall be prescribed by the Insurance Commissioner under the provisions of this act only upon notice and after hearing to all parties affected thereby, and rules and regulations relating thereto shall be promulgated by the Insurance Commissioner at least six months before the effective date thereof.