Any common carrier that shall willfully neglect or refuse to obey or conform to any order of the commission made pursuant to either of sections 35 or 36 shall be liable to a penalty in the sum of 500 dollars, and to a like penalty for every week thereafter until such order shall have been complied with: Provided, That in cases in which an application for rehearing shall be made, or an action in court shall be begun and prosecuted in good faith and with diligence, the liability for the continuing penalty herein prescribed shall not apply or begin until after the decision of the commission or rehearing of the final order of the courts in such action.
MCL 462.38