No insurer, or employee thereof, and no broker or agent shall knowingly charge, demand, or receive a premium for any policy of insurance except in accordance with the respective rating systems on file with, and approved by, the commissioner. No insurer, or employee thereof, and no broker or agent shall pay, allow or give, or offer to pay, allow or give, directly or indirectly, as an inducement to insurance or after insurance has been effected, any rebate, discount, abatement, credit, or reduction of the premium named in a policy of insurance, or any special favor or advantage in the dividends, or other benefits to accrue thereon or any valuable consideration or inducement whatever not specified in the policy of insurance, except to the extent that such rebate, discount, abatement, credit, reduction, favor, advantage, or consideration may be provided for in rating systems filed by, or on behalf of, such insurer and approved by the commissioner. No insured named in a policy of insurance, nor any employee of such insured, shall knowingly receive or accept, directly or indirectly, any such rebate, discount, abatement, or reduction of premium or any such special favor, or advantage, or valuable consideration, or inducement. Nothing contained in this section shall be construed as prohibiting the payment of commissions or other compensation to regularly appointed and licensed agents and to brokers duly licensed by this state nor as prohibiting any participating insurer from distributing to its policyholders dividends, savings or the unused, or unabsorbed, portion of premiums and premium deposits.