Gemini Free Trial Canceled but Subscription Fee Still Charged on Apple

I am an Apple user and started a one-month free trial subscription for the Gemini app. I canceled the subscription approximately five days before the trial period ended, but the cancellation did not appear in the system and the subscription continued as if it were still active. On January 12 at 10:18 PM, a subscription fee of approximately $26 was charged to my card. Since I canceled the subscription before the end of the free trial, I do not accept this charge. The subscription was purchased through my Apple ID associated with the email address o*******@gmail.com. I submitted a refund request through Apple, but I was informed that refunds for subscriptions are difficult and that my request would likely be rejected. I do not want to be charged when I canceled the subscription before the trial period expired. For this reason, I am requesting a full refund of the approximately $26 that was charged and the permanent cancellation of my Gemini subscription.