Any person subject to any order may file a written petition with the Secretary, stating that any such order or any provision of such order or any obligation imposed in connection therewith is not in accordance with law and praying for a modification thereof or for an exemption therefrom. The petitioner shall thereupon be given an opportunity for a hearing upon such petition, in accordance with regulations issued by the Secretary. After such hearing, the Secretary shall make a ruling upon the prayer of such petition which shall be final, if in accordance with law.