No insurance policy, certificate, contract, agreement, or rate schedule, except as is otherwise provided, may be issued, nor may any application, rider, or endorsement be used in connection therewith until the expiration of sixty days after it has been filed unless the commissioner gives written approval. The commissioner may extend the sixty-day period for an additional period not to exceed fifteen days if the commissioner gives written notice within the sixty-day period to the insurer which made the filing that the commissioner needs the additional time for the consideration of the filing.