Cancelled eDreams Prime Immediately but Refund Request Ignored

I am writing regarding an unauthorized eDreams Prime charge of €89 that was taken from my credit card on 16 June, after I purchased a flight through your platform. I only intended to buy a single flight, and at no point did I knowingly agree to or wish to subscribe to eDreams Prime. The card I used for the flight was later charged for a Prime membership without my clear and informed consent, which I consider misleading and unacceptable. As soon as I noticed the Prime fee, I cancelled the membership the same day, so the subscription was effectively unused and should entitle me to a refund for the remaining 364 days. Your customer service has only mentioned a pro-rata approach and has not provided a fair or transparent solution despite the immediate cancellation and the fact that I did not knowingly sign up. My bank has advised me to first resolve this directly with you before proceeding with a chargeback, but your team has ignored my legitimate request and has not taken my complaint seriously, which makes the situation feel like fraud and a deliberate practice rather than an honest mistake. I request a full refund of the €89 eDreams Prime fee and written confirmation that my Prime subscription has been completely cancelled and will not be renewed or charged again in the future. I also ask that you review and correct your subscription practices so that customers in the EU are clearly and transparently informed, and not signed up to paid memberships in a way that feels deceptive. I expect this issue to be resolved promptly and in good faith.