To be able to get their handphone number is the best. call them personally so that you can get a response faster.
the official channel is usually manned by a NSF who is just operating by the books as mention by some and the chances of a deferment/time off is usually slim.
unit commanders are usually given the discretion to act based on individual's reasons for time off request. with proper documents and reasonable length of time off i don't see why your unit is so anal to deny you.
during my ICT (ATEC stage II) i seen some men with urgent matters to attend to, took half day time off, afternoon join in the battle after being ferried in my trainers.