The other day someone said it takes 15 days to reach the north zone of your country to another place in the north zone, so Sydney should take longer (unless they are doing emails only now).
You should try contact them since it has been over 2 months for you. Do you know when they received your application. If you don't hear after aug 15th, then definitely contact them. Just not sure if you should contact them now or not.
Lets wait for someone else to answer.