Trial Version payment

The trial period is 7 days. Cancel within your trial period and you won't be charged.

How to cancel

https://helpx.adobe.com/manage-account/using/cancel-subscription.html

Once you've subscribed, Adobe has a clear cancellation and refund policy

https://www.adobe.com/legal/subscription-terms.html

"Cancellation Terms
You can cancel your subscription anytime via your Adobe Account page or by contacting Customer Support*. If you cancel within 14 days of your initial order, you’ll be fully refunded. Should you cancel after 14 days, you’ll be charged a lump sum amount of 50% of your remaining contract obligation and your service will continue until the end of that month’s billing period."

Follow those time frames and you'll be refunded.