The term of any credit life insurance or credit disability insurance shall commence on the date when the debtor becomes obligated to the creditor, or the date the debtor applies for such insurance, whichever is later, except that where a group policy provides coverage with respect to existing obligations, the insurance on a debtor with respect to such indebtedness shall commence on the effective date of the policy. Where evidence of insurability is required and such evidence is furnished more than ninety (90) days after the date when the debtor becomes obligated to the creditor, the term of the insurance may commence on the date on which the insurance company determines the debtor to be insurable, and in such event there shall be an approximate refund or adjustment on any charge to the debtor for insurance. The term of such insurance shall not extend more than thirty (30) days beyond the scheduled maturity date of the indebtedness, except when extended without additional cost to the debtor.