new customers only, you can just keep making accounts i guess
Comes with free sim card as well
UPDATE: no need to port number, tried and works fine
Edit 25/10: Available again (thanks pennypincher98), expires at midnight.
Technically anyone can be a 'new' customer - worked on the same email that got the birthday deal.
Note: This actually expires 1 day sooner than the birthday deal despite being several days later
Voucher expires at 3:00AM AEDT on 20/11/2017
Update (26/10): Available for 2 more hours (thanks VKV)