Unauthorised charges of Apple Music

Have you already been charged by Apple?

If you don't recognize a charge - Apple Support

Or did you get a message or email, informing you about getting charged by Apple?

This might also be a phishing attempt:

Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

You can check all your ongoing subscriptions in your Apple ID settings:

If you want to cancel a subscription from Apple - Apple Support

You should contact the official Apple Support about that, only they can look into your personal details and find the issue.

Use this link as a start:

Subscription and Billing - Apple Support

Or give the a call:

Contact Apple for support and service - Apple Support

Did you subscribe to Apple Music Family, which would cost that amount?

Apple Music - Apple (AU)