If any such contract, agreement or arrangement shall, in the opinion of the Commission, in any way be in violation of any of the provisions of this chapter, the Commission shall forthwith notify the railroad companies in writing of its objections thereto, specifying such objections. If the railroad companies shall fail or neglect, within five days after receipt of such notice, to amend and alter such contract, agreement or arrangement in a manner satisfactory to the Commission, the Commission shall thereupon call upon the Attorney General to institute and conduct such legal proceedings as may be necessary to enforce the penalties prescribed in this chapter for such violations of its provisions.