In my case, amount was deducted the next day of ITA submission and same date was showing as ITA lodge date. But before doing that, they will check if your application is complete with all the basic documentations such as (Certified copies of) Birth certificate,passport , IELTS, police certificates, Medicals , Signed forms etc..
It may slightly vary from case to case.. I was notified by my bank about the deduction. Also, you will start getting e-mail notifications and you can check the status online as well.. Look for the Lodgement date online. All the best!