Whenever, after hearing upon complaint or its own motion, the commission finds that any rate of any contract carrier by motor vehicle, or any regulation or practice of any such carrier affecting such rate for the transportation of passengers or property, contravenes the public policy as set forth in section 2501 (relating to declaration of policy and definitions), the commission may prescribe such minimum rates or such regulations or practices as in its judgment may be just and reasonable to promote the public interest. Such minimum rates or such regulations or practices so prescribed by the commission shall not be inconsistent with the policy declared in section 2501, and the commission shall give due consideration to the cost of the service of such carriers, and to the effect of such minimum rates or such regulations or practices upon the transportation of passengers or property by such carriers, and diversion of the business of any common carrier by motor vehicle to other forms of transportation. All complaints to the commission under this section shall state fully the facts complained of and the reasons for such complaints, and shall be made under oath or affirmation.