If within 15 working days from service of the citation issued by the registrar, the licensee or applicant for licensure fails to notify the registrar that he or she intends to contest the citation, the citation shall be deemed a final order of the registrar and not be subject to review by any court or agency. The 15-day period may be extended by the registrar for cause.
Ca. Bus. and Prof'l. Code § 7099.4