Tenn. Code Ann. § 65-4-115: Unjust practices and unsafe services prohibited

No public utility shall adopt, maintain, or enforce any regulation, practice, or measurement which is unjust, unreasonable, unduly preferential or discriminatory, nor shall any public utility provide or maintain any service that is unsafe, improper, or inadequate, or withhold or refuse any service which can reasonably be demanded and furnished when ordered by the commission.