An appeal to the Public Service Commission of the reasonableness of any rate, charge, or assessment of the Commission may be taken by: an individual who has a financial interest in the appeal; or the county council of Montgomery County or Prince George’s County. Under regulations of the Public Service Commission, on appeal under paragraph (1) of this subsection, the Public Service Commission shall determine the reasonableness of the rate, charge, or assessment of the Commission. An appeal under this section shall be taken by filing a written complaint within 30 days after the date on which the Commission set the rate or fixed the charge or assessment.