Money was debited (by Apple), I don't know why

First see if you can identify the charge

1. To see your purchase history, go to reportaproblem.apple.com.
2. Sign in with your Apple ID.
3. A list of purchases will appear. To see family members' purchases, select the Apple ID button and choose a family member.
4. To see the full receipt, including tax, tap or click the date. Multiple purchases, including subscriptions, may be grouped into one charge.

If the charge is for a subscription that you no longer want, you can cancel the subscription. Find out where else you can view your Purchase History.

Click on the link below, you can

• View your purchase history

• Cancel a subscription

• Request a refund

• Verify unfamiliar charges

• Add or remove a payment method

Subscriptions and Billing - Official Apple Support