eDreams Charged Me for a Membership I Never Subscribed to and I Got No Full Refund

On September 23, I purchased a flight ticket from Sydney to Melbourne through Jetstar and it redirected me to eDreams. Without my knowledge or consent, eDreams charged me $89.99 for a Prime membership, which I never subscribed to. Their customer service department refused to resolve this issue stating they could credit me 50% leaving a $45 credit for future travel I need to book through them for future travel. They would not cancel the subscription or the 50% refund and credit would not go through. I did not agree to this membership which I am now stuck with and I’m demanding a full refund of the unauthorized charge. Prime customer service was unable to help advising that e-dreams is a separate division & needs to issue a full refund. This situation is extremely frustrating, and I need eDreams to take immediate action to return my money. I want my full $89.99 refund and not just 50%. Please assist me in getting this resolved as soon as possible!