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.