Section 27D. In any case where the court denies a request for waiver, substitution or payment by the commonwealth of fees and costs, pursuant to section twenty-seven C or any other provision of law, the applicant may take an appeal as hereafter provided. If the matter arises in the superior, the land, the probate or the housing court departments, the appeal shall be to a single justice of the appeals court at the next sitting thereof. If the matter arises in the juvenile court department, the appeal shall be to the superior court sitting in the nearest county or in Suffolk county. If the matter arises in the district court or Boston municipal court departments, the appeal shall be to the appellate division. Upon being notified of the denial the applicant shall also be advised of his right of appeal, and he shall have seven days thereafter to file a notice of appeal with the clerk or register. Upon receipt of notice of appeal timely filed the clerk or register shall forthwith notify the judge or justice, who shall within three days set forth his written findings and reasons as provided in paragraph (4) of section twenty-seven C. The court denying the request may, with or without motion, stay proceedings pending appeal or issue any other order or process to preserve the rights of the parties pending the appeal. The clerk or register shall then forward the affidavit and request, the court's findings and reasons for denial and any other documents on file relevant to the appeal, to the clerk of the court deciding the appeal, who, upon receipt thereof, shall refer the matter to the court for speedy decision and shall promptly notify the applicant of such decision. The court deciding the appeal may enter a stay or revoke an existing stay or other order, and its decision shall be final with respect to such request.''