Edreams Prime membership ****

I recently booked flight tickets through Edreams. A few days later i received a bank purchase notification with Edreams notification. Upon investigation via their website and mobile app it was a Prime membership which i apparently joined even though am certain i never signed up to this and its an annual subscription with monthly payments. Apparently i can cancel but however i will be debited for the whole year and this to me is daylight *******, **** of the highest order. Tell me why i would subscribe to a service that i will be tied in for the whole year yet i rarely travel by flight?