If a hearing is not requested within fifteen days after the receipt of the notice given pursuant to § 34-21-35 , the agency shall issue its order finding that the violation of the chapter or the rules and regulations of the agency has or has not occurred, and shall forthwith forward a copy of such order by registered or certified mail to said person. Such order shall be final and may not be appealed from. Source: SL 1967, ch 107 , § 5 (b); SL 1972, ch 15 , § 3.