(a) In any case pending before it, the commission, in addition to its now existing authority to do so, is authorized to issue an order permitting its employees and agents to take depositions and otherwise obtain discovery of any matter, not privileged, which is relevant to the subject matter involved in the investigation, proceeding, or petition before the commission, in the same manner prescribed in Chapter 11 of Title 9 for discovery in civil actions. In any case involving an application of a gas company to establish just and reasonable rates pursuant to Code Section 46-2-23.1 or 46-4-154, intervenors who are granted party status pursuant to Code Section 46-2-59, as well as the gas company subject to the particular proceeding, shall have all discovery rights available under Chapter 11 of Title 9.

(b) The commission, its agents and employees as directed by the commission, and intervenors and gas companies which are granted discovery rights under subsection (a) of this Code section are authorized to petition the Superior Court of Fulton County for all orders, injunctions, and subpoenas necessary to carry out the provisions of this Code section which would otherwise be authorized or necessary under Chapter 11 of Title 9; and the judges and clerks of the court are authorized to issue all such orders, injunctions, and subpoenas and to take all other actions necessary to carry out this Code section which would otherwise be authorized or necessary under Chapter 11 of Title 9.

(c) In addition to the sanctions which may be imposed under Code Section 9-11-37, the Superior Court of Fulton County is further authorized to extend the period of suspension of the operation of any new schedules and defer the use of such rates, charges, classifications, or service beyond the time authorized by Code Section 46-2-25, if the court, upon application of the commission, determines that the failure of any regulated utility to comply with a discovery request of the commission, its agents, or its employees is unreasonable and requires such extension. No such extension of the period of suspension shall be considered by the court unless the utility has failed completely to respond to a valid deposition or discovery request.

(d) Any application or petition made by the commission, its agents, or its employees pursuant to this Code section shall be heard within 20 days of the filing of the application or petition, irrespective of whether any response to the application or petition has previously been made, and shall be disposed of promptly.