Section 12A. Any person aggrieved by a determination of the commission, or by the finding of a person or persons making a review, if the provisions of section twelve are included in a local ordinance or by-law, may, within twenty days after the filing of the notice of such determination or such finding with the city or town clerk, appeal to the superior court sitting in equity for the county in which the city or town is situated. The court shall hear all pertinent evidence and shall annul the determination of the commission if it finds the decision of the commission to be unsupported by the evidence or to exceed the authority of the commission, or may remand the case for further action by the commission or make such other decree as justice and equity may require. The remedy provided by this section shall be exclusive but the parties shall have all rights of appeal and exception as in other equity cases. Costs shall not be allowed against the commission unless it shall appear to the court that the commission acted with gross negligence, in bad faith or with malice in the matter from which the appeal was taken. Costs shall not be allowed against the party appealing from such determination of the commission unless it shall appear to the court that such party acted in bad faith or with malice in making the appeal to the court.