Each property and casualty insurance policy approved by the Insurance Commissioner shall contain a provision describing the process for premium refund if the insured cancels the policy before the end of the policy period as defined in the policy. The provision is to be included in the policy, or by rider or endorsement attached to the policy. The policy does not have to contain the exact wording of this section or any other exact wording. Language which is substantially similar to this section shall be considered to be in compliance with this section.