Generally. Any person or persons, jointly or severally aggrieved by any decision of the board of zoning and adjustment or any office, department, board, or bureau of the municipality may present to the Circuit Court of Cass County, Missouri, petition duly verified, setting forth that such decision is illegal, in whole or in part, specifying the grounds of the illegality. Such petition shall be presented to the court within thirty (30) days after the filing of the decision in the office of the city clerk. Upon presentation of such petition, the court may allow a writ of certiorari directed to the board of zoning and adjustment to review such decision of the board of zoning and adjustment and shall ascribe therein the time within which a return thereto must be made and served upon the relator’s attorney, which will not be less than ten days and may be extended by the court. The allowance of the writ shall not stay proceedings upon the decision appealed from, but the court may, upon application, on notice to the board and on due cause shown, grant a restraining order. The board of zoning and adjustment shall not be required to return the original papers acted upon, but it shall be sufficient to return certified or sworn copies thereof or of such portions thereof as may be called for [in] such writ. The return shall concisely set forth such other facts as may be pertinent and material to show the grounds of the decision appealed from that shall be verified. If, upon the hearings, it shall appear to the court that testimony is necessary for the proper disposition of the matter, it may take additional evidence or appoint a referee to take such evidence as it may direct and report same to the court with his findings of fact and conclusions of law, which shall constitute a part of the proceedings upon which a determination of the court shall be made. The court may reverse or affirm, wholly or partly, or may modify the decision brought up for review. Costs shall not be allowed against the board unless it shall appear to the court that it acted with gross negligence or in bad faith or with malice in making the decision appealed from. All issues in an [any] proceedings under Sections XXVIII and XXIX shall have preference over all other civil actions and proceedings.