(b) Any handler subject to an order may file a written petition with the commission stating that any such order or any provision of any such order or any obligation imposed in connection therewith is not in accordance with law and praying for a modification thereof or to be exempted therefrom. He shall thereupon be given an opportunity for a hearing upon such petition, in accordance with regulations made by the commission. After such hearing, the commission shall make a ruling upon the prayer of such petition which shall be final, if in accordance with law.
(c) The district courts of the United States in any district in which such handler is an inhabitant, or has his principal place of business, are hereby vested with jurisdiction to review such ruling, provided a complaint for that purpose is filed within thirty days from the date of the entry of such ruling. Service of process in such proceedings may be had upon the commission by delivering to it a copy of the complaint. If the court determines that such ruling is not in accordance with law, it shall remand such proceedings to the commission with directions either (1) to make such ruling as the court shall determine to be in accordance with law, or (2) to take such further proceedings as, in its opinion, the law requires. The pendency of proceedings instituted pursuant to this subdivision shall not impede, hinder, or delay the commission from obtaining relief pursuant to section seventeen. Any proceedings brought pursuant to section seventeen, except where brought by way of counterclaim in proceedings instituted pursuant to this section, shall abate whenever a final decree has been rendered in proceedings between the same parties, and covering the same subject matter, instituted pursuant to this section.