Any client admitted to a facility or to a program of nonresidential habilitation under Article V of this Chapter or his guardian, attorney, or nearest adult relative on his behalf may at any time petition the court for transfer to a different facility or program of nonresidential services. If the client is in a private facility, the facility may also petition for transfer. An order for admission to a facility shall not be entered under this Section if the original order did not authorize such admission unless a hearing is held pursuant to Article VI of this Chapter.