N.Y. Public Service Law § 75

§ 75. Defense in case of excessive charges for gas or electricity. If\nit be alleged and established in an action brought in any court for the\ncollection of any charge for gas or electricity, that a price has been\ndemanded in excess of that fixed by the commission or by statute in the\nmunicipality wherein the action arose, no recovery shall be had therein,\nbut the fact that such excessive charges have been made shall be a\ncomplete defense to such action.\n