Unexpected Charge for 1-Year Super Duolingo Subscription—Requesting Refund

During my time on Duolingo, I came across an opportunity to try out Super Duolingo for free, and I decided to give it a go. I was informed that I would be notified two days prior to the trial's conclusion, yet I was unexpectedly billed for an entire year without any prior warning or consent. There was a lack of communication, and I was unable to locate a contact number to address this matter. It is extremely irresponsible to take a full year's payment without notifying me. I would like to request a refund of ₺839.99. I kindly request a refund of my funds.