Certificates, permits and licenses shall be effective from the date specified therein and shall remain in effect until terminated as herein provided. Any such certificate, permit or license may, upon application of the holder thereof, in the discretion of the commission be amended or revoked, in whole or in part, or may, upon complaint or on the commission’s own initiative, after notice and hearing, be suspended, changed or revoked, in whole or in part, for willful failure to comply with any provision of this chapter or with any lawful order, rule or regulation of the commission promulgated thereunder, or with any term, condition or limitation of such certificate, permit or license; provided, that no such certificate, permit or license shall be revoked (except upon application of the holder) unless the holder thereof willfully fails to comply within a reasonable time, not less than 30 days, to be fixed by the commission, with a lawful order of the commission, made as provided in this chapter, commanding obedience to the provisions of this chapter or to the rules or regulations of the commission thereunder, or to the term, condition or limitation of such certificate, permit or license, found by the commission to have been violated by such holder.