N.J. Stat. Ann. § 56:8-2.19

The provisions of section 3 shall not apply to retail mercantile establishments or departments that have a policy of providing, for a period of not less than 20 days after the date of purchase, a cash refund for a cash purchase or providing a cash refund or issuing a credit for a credit purchase, which credit is applied to the account on which the purchase was debited, in connection with the return of its unused and undamaged merchandise.