Voucher - HAHA forget it

I was so happy when I was promised a $ 300 voucher. They told I should let some days pass and then get my voucher from the homepage. That's the good story so far. Of course it didn't work out at all and I called the hotline. Several times. The staff is incompetent and unfriendly and, seriously, I just came to Australia two months ago but my English is definitively a lot better. And how often do I need to repeat that I didn't get a voucher number so far? This is simply unbelievable. I'm a psychologist and I'm very patient usually. It did never happen to me that I ended up shouting at my phone. Of course they couldn't find any voucher number in their system and so I should let some time pass and then call again. I'm absolutely sure that I won't get my voucher in time, cause I'm leaving in two months and to be honest, the only thing I can do is to avoid flying with Jetstar in the future and tell people about this page.