The passport of my wife, Zhang Li,a permanent citizen of Australia, will expire on the 2017-06-17

We have already booked a return flight to China from 2017-06-01 until 2017-06-30. How can renew her passport as soon as possible? We have tried phoning the Chinese Consulate in Sydney many times with no success.
Can she fly to China a renew the passport in Xi'an when we get there? Or what other ideas can you provide?