Is there a way to cancel a subscription after the free trial period?

You can cancel an Apple subscription at any time.

See How to cancel a subscription from Apple

How to cancel a subscription on your iPhone, iPad, or iPod touch

1. Open the Settings app.
2. Tap your name.
3. Tap Subscriptions.
4. Tap the subscription that you want to manage. Don't see the subscription that you're looking for?
5. Tap Cancel Subscription. (Or if you want to cancel Apple One but keep some subscriptions, tap Choose Individual Services.) If you don’t see Cancel, the subscription is already canceled and won't renew.

If you are still within the free trial period be sure to cancel before the trial ends or you will be charged for the first period (month?) of the paid subscription.

Subscribers are responsible for their own accounts and timely cancellations, but you could try your luck. Go to Request a refund for apps or content that you bought from Apple and make a request for a refund.