Hello,
Your Australia Post shipping plugin seems to be correctly configured and when I test it on my end, international services are available.
Can you send us a temporary back-end access through our contact form so that we can directly test it :
www.hikashop.com/support/contact-us.html
I should also say that some of the shipping options are no longer offered by Australia Post. They recently changed their postal offerings again so possibly something in this area is the problem.
When I test it on my end I actually have every international shipping services. But we will check it, thanks for your feedback.