Apple One Trial Subscription

Here are more possibilities as outlined in this support article: If you can't redeem your promotion for an Apple subscription - Apple Support

- Most offers are available for only a limited time, and for first-time subscribers. If you were a subscriber before or participated in an Apple service through a family sharing plan you may not be eligible to redeem the offer.

- If you or a family member already redeemed the offer, you can't redeem it again. You may be billed immediately for a free trial if you or a Family Sharing member has already once had a free trial for that item. In that case you will see immediate subscription commencement information on the authorization page.

- To redeem some promotions, you need to sign in with your Apple Account on the eligible device.

Once you cancel a free trial Apple may not be able to restore it. You can try to contact them (note that the links below are direct ones and do not route you through Google as I note ones in another reply do).

This support page has information about Apple support and service ➔ Contact Apple Support - Apple Support If live support options (chat and/or telephone) are available they will show near the bottom left.

- Telephone numbers may only work when calling from the same country.

- Chat options (telephone numbers appear as active links, not plain text) may depend upon cellular connectivity. If a number shows as an active link, click on it to see additional options.

- If chat is not available on the top level support page, try selecting your hardware and narrow down your issue to see if a support article offers a support link offering chat. For example, the contact support link on this page Check your Apple Account balance - Apple Support offers a chat link about emptying account balance even on a computer where the top level page does not offer any chat.

With an iPhone, iPad, or Vision, you may be able to chat using the Apple Support App if it is available in your country —> https://apps.apple.com/app/apple-support/id1130498044

You can get help or try to restore a lost promotional offer by contacting Apple Support directly through the Apple Support App or via Apple Support Contact.

Why the Charge Happened and What to Know

• One Trial Per Account: Apple free trials for Apple One or individual services (like Apple Music, Apple TV+, or Apple Arcade) are strictly limited to first-time subscribers or specific returning status rules. 
• System Flagging: Once you sign up and the system registers an active or canceled transaction—even if you were billed incorrectly and later refunded—Apple's automated billing system often flags the account as having "consumed" or forfeited the introductory offer. 
• Automatic Roll-In Rules: If you already paid for or used individual services bundled into Apple One, those service histories can interact with trial eligibility.