eDreams Displayed €0 Fare Difference, Then Quoted 4 Different Prices

I am submitting this complaint regarding the handling of my flight change request by eDreams. My reservation includes a flight from Istanbul to Vienna on 5 June and a return flight from Vienna to Istanbul on 7 June, operated by Ajet and Pegasus. When booking, I purchased both the Premium (Prime) membership and the Flex package to benefit from the flight change flexibility advertised by eDreams, paying approximately £6.32 for the Flex package in addition to my ongoing Prime membership. On 2 June at 10:28 AM, I submitted a request through the eDreams app to change my return flight to 11 June. During this process, the application displayed alternative flight options with a €0 fare difference, and based on the information presented by eDreams at that moment, I confirmed and submitted the request. Shortly after, I received a confirmation email that my change request had been received. However, my request then remained in “processing” status. On the same day, between approximately 3:00 PM and 6:00 PM on 2 June, I contacted customer service three times by phone. In these calls, I was given completely different fare difference amounts for the same change request: first €43, then around €90, then over €100, and finally €68. Receiving four different prices for the exact same request clearly shows a lack of transparency, consistency, and reliability in the information provided by eDreams. Despite having an active Prime membership and having paid for the Flex package, I was only able to reach first-level customer service agents who repeatedly stated that they had no authority to resolve the issue or to make any exception in line with what the app had shown. This situation raises serious doubts about the real value and purpose of the Prime and Flex services for which I have already paid. Furthermore, the 24–48 hour processing period for such change requests was not clearly disclosed or highlighted before I submitted my request in the app. Because of this prolonged and unclear processing period, I have been unable to make alternative travel arrangements, while ticket prices on the market continue to increase, causing me financial loss and unnecessary stress. I therefore request that my flight change be processed according to the conditions displayed in the eDreams application at the time I submitted my request, including honouring the €0 fare difference shown then. I also request a clear and written explanation for the contradictory fare information and inconsistent amounts provided by customer service during my calls. My booking reference is 24892769935. If this matter is not resolved promptly and in line with the conditions that were displayed to me in the app, I reserve the right to pursue all available legal and consumer protection remedies.