Tess Crawley has some fantastic resources at her website https://tesscrawley.com.au/ in relation to Medicare and Better Access compliance including a free Better Access survival guide for mental health professionals which can be accessed here https://tesscrawley.com.au/product/better-access-survival-guide/
There is also a very reasonably priced pre-recorded training course that's available here https://tesscrawley.com.au/product/medicare-better-access-training/
The survival guide is great and takes you through the entire Medicare referral, billing and reporting process and also includes information on Medicare audits and examples of scenarios that can be red flags to Medicare which may lead to an audit of a practise. If you have any doubts about your processes and compliance with Medicare and Better access (who doesn't!) I encourage you to visit her site and download the free guide or take the training course.