The corporation commission [public regulation commission] may prescribe reasonable maximum rates for the transportation of oil and the products derived therefrom, where such products are transported by a pipeline common carrier from any point in New Mexico to an ultimate destination in New Mexico, provided, in the event the reasonableness of such rates are [is] contested in the manner provided by law, the burden of proof to show the unreasonableness of such rates shall be upon the person, firm, association or corporation contesting the same.
NMS § 70-3-1