(a) A landlord who violates a commission rule relating to submetering of electric utilities consumed exclusively in a tenant's dwelling unit or a rule relating to the allocation of central system utility costs or nonsubmetered master metered electric utility costs is liable to the tenant for:
(1) three times the amount of any overcharge;
(2) a civil penalty equal to one month's rent;
(3) reasonable attorney's fees; and
(4) court costs.
(b) A landlord is not liable for the civil penalty provided by Subsection (a)(2) if the landlord proves that the landlord's violation of the rule was an unintentional mistake made in good faith.