If you need to un-combine sections have been combined in error, please back up and download any content you have added to the course and contact the moodle support team (moodle@bilkent.edu.tr).
Be warned, though, that to un-combine your course, the admins must delete the combined course. Be advised that, even if you have backed up your course, there will be no “user data” in the backup. Deleting the course will therefore lead to losing any work already done on the course by the teacher(s) and student(s)!