Ryanair cancelled then reinstated flights

tullie

Hi, I wondered if anyone could help please? Ryanair cancelled my flights from Birmingham to Sofia in December, I was given the option to transfer my flghts to leave from Stansted which I did. The Birmingham flight is now back on the Ryanair website (same times and dates) and I contacted them to be put back on the flight I originally booked but Ryanair are saying I have already had my free change. Is there anything I can do to get back onto my original flight without having to pay change fees? We fly back 4th Jan so don't qualify for the zero change fee unfortunately TIA