Duolingo Charged for 1-Year Super Membership Without Notification

While using Duolingo, I was offered a free trial of Super Duolingo, which I accepted. They promised to notify me two days before the trial ended, but they charged me for a full year’s membership without any warning or notification. I didn’t receive any alert, and there’s no contact number available for support. I am requesting a refund for this unauthorized charge. It’s unacceptable to be billed for a one-year subscription without prior notice. Please refund my money immediately, as this charge was made without my consent or any prior notification.