A claim or defense based on usury or excessive loan charges, commitment fees, or brokerage commissions will not be sustained where the person against whom the claim or defense is made, in computing and making such charges, fees, or commissions, has relied on a statute, or a rule or regulation promulgated by an administrative agency, or on the final order of any such administrative agency in a proceeding involving such person.
T.C.A. § 47-14-116