An administrative unit may postpone a hearing for good cause only if a written request for postponement is filed with the administrative unit not later than 10 days before the date of the hearing. If a request for postponement is received later than 10 days before the date of the hearing, the administrative unit shall deny the request unless it determines that there were extenuating circumstances which justified the delay. The failure of a respondent, claimant, or applicant to retain counsel or to timely request a subpoena may not be considered good cause under this regulation. A request for postponement based on failure to obtain service on a witness may not be granted if the party has failed to comply with Regulation .12 of this chapter.