The Division has broad discretion in processing representation petitions, and its discretion is generally not subject to judicial review under M.G.L. c. 30A, Section 14. Jordan Marsh v. Division of Labor Relations, 312 Mass. 567, 600-601 (1942); City Manager of Medford v. Division of Labor Relations, 353 Mass. 519, 523-24 (1968); Worcester Industrial Technical Inst. Instructors Assn. Inc. v. Division of Labor Relations, 357 Mass. 118, 120-121 (1970). Sullivan v. Division of Labor Relations, 5 Mass. App. Ct. 532, 535 (1977). The general rule that Division decisions in representation matters are not judicially reviewable under Chapter 30A is premised on the fact that they are not final decisions in an adjudicatory proceeding within the meaning of Chapter 30A. The courts have recognized three limited exceptions to this general rule: 1) if the Division exceeds its jurisdiction; 2) if there is an extraordinary circumstance for varying the general rule; or 3) if there is a risk of special injury to the public interest. See, e.g., Local 1111, International Association of Fire Fighters, AFL - CIO v. Division of Labor Relations, 14 Mass. App. Ct. 236, 238 (1982), citing City Manager of Medford at 523-24. Therefore, an employer that wishes to challenge the Division's decision in a representation case must do so by refusing to bargain and raising the issue as a defense to a prohibited labor practice charge. See, e.g., Town of Wenham, 44 Mass. App. Ct. 195 (1998).