Calm down now, calm down.
It seems the month they gave you to supply the document is a standard reply. We've had a couple of requests for them for further evidence and the month is what they've given us too. As for the Australian police certs - can't be sure - but if our UK one is anything to go by it took 6 mths!! Ring your case officer and explain, there's nothing you can do if there's nothing you can do - it's not you holding up the process. The main thing is to keep you case officer informed - then all should be well.
And by the way did I say calm down