I received an offer for 3 months free but I have been billed? Please advise

Greetings thisiscracra,

If you were charged when signing up for a free trial, then it sounds like you may not have been eligible for the trial offer. Many trial offers require the user to be a new subscriber of the service to receive the free trial. If you have had Apple Music in the past, then that could prevent you from the new trial offer.

Check out the terms and conditions for the current promotions, which outline that the user must be a new subscriber to Apple Music to receive the trial offer in the following article: Offers - Apple

New subscribers get 6 months of Apple Music free with eligible AirPods, HomePod speakers, or Beats headphones, subject to the terms and conditions herein.

You can visit the Report a Problem website if you'd like to request a refund. Check out those steps here: Request a refund for apps or content that you bought from Apple - Apple Support

How to request a refund

1. Sign in to reportaproblem.apple.com.

2. Tap or click "I'd like to," then choose "Request a refund." 

3. Choose the reason why you want a refund, then choose Next.

4. Choose the app, subscription, or other item, then choose Submit. If you were charged for a subscription that you no longer want, you can also cancel the subscription.

Reach out to Apple Support directly if further help is needed with investigating the Apple Music trial offer. You can use the following link to reach out: Contact - Official Apple Support

Kind regards.