Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well. Apologies for the delayed response.
Please note that both India and Australia come under the same Zone (in terms of billing).
See : Bandwidth pricing.
To understand, why the bill was generated using 'AU East', we will need a specialized 1:1 session, where a support engineer can have access to your subscription. If you have a support plan you may file a support ticket, else please do let us know, we will try and help you get a one-time free technical support
Cheers,
Kapil