

Birth certificate authentication at Chinese consulate in Sydney.
We need to get my daughter's birth certificate authorised so we can get a family visa for a Job I will be starting. We will be in Australia for only a couple of weeks between my old job in Japan and new one in China. The website for the Sydney consulate says they won't accept authorization applications by post. However our home is a very very long way from Sydney and it is not practical in terms of time or cost for us to present in person and then wait for 4 days while they stamp the document (already DFAT authorized).
The Sydney consulate seems to be impossible to contact - I've sent two emails and tried calling the numbers on multiple occasions with no response at all. My question is, can I fly to Sydney and present the document in person along with a stamped self addressed envelope and then have them return it by express post? 4 days in a hotel in Sydney is an outrageous expectation to have, given the costs and distances involved (we're in and out of Australia via Gold Coast, but are from northern NSW).