Nothing in §§ 58-33-14 and 58-33-15 shall be construed as including within the definition of discrimination or rebates, in the case of life insurance and health insurance policies issued on the industrial debit, preauthorized check, bank draft, or similar plans, making allowance to policyholders who have continuously for a specified period made premium payments directly to an office of the insurer or by preauthorized check, bank draft, or similar plans, in an amount which fairly represents the saving in collection expense.
SDCL 58-33-18