(a) Except as otherwise provided in this section, a public utility may not discontinue or abandon a service for which a certificate has been issued by the commission unless upon the application of the public utility and if, after notice and opportunity for hearing, the commission finds that the continued service is not required by public convenience and necessity. Any interested person may file with the commission a protest or memorandum of opposition to or in support of discontinuance or abandonment. The commission may authorize temporary suspension of a service or of part of a service.
(b) Upon complaint or upon its own motion, the commission may reinvestigate a previously authorized discontinuance, abandonment, or suspension of a service of an operating public utility. If, after providing notice and an opportunity for a hearing, the commission finds that the public convenience and necessity require the service to be resumed, it may order the public utility to again provide the service.