Can't Get Ahold of Anyone @ Kulula

I purchased a fridge and received a R6000 gift voucher. I chose to use it on Kulula tickets as it was 1 of the voucher options. I tried calling their *** number buy when it reaches 4 minutes of waiting the call drops. I emailed them on the *** address, twice and no one has rep****!!! We want to fly in March. The Voucher T's & C's state you have to book 4 weeks before the flight!! How an I suppose to do that when I can't get ahold of anyone from Kulula????