Matter of Bozena Zmijewska, 24 I. & N. Dec. 87 (BIA 2007) (BIA lacks authority to apply an "exceptional circumstances" or other general equitable exception to the penalty provisions for failure to depart within the time period afforded for voluntary departure under INA 240B(d)(1), 8 U.S.C.A. 1229c(d)(1); noncitizen has not voluntarily failed to depart the United States under INA 240B(d)(1) when the person, through no fault of his or her own, was unaware of the voluntary departure order or was physically unable to depart within the time granted).