I’ve never heard of that either sadly- do you have travel insurance? Maybe you can claim the cost of the flight back that way. Otherwise as the trip isn’t until September, maybe the airline will show some compassion and offer at least a partial refund I hope- they would still have plenty of time to sell the seats. Also, depending on your reason, if it were medical and verified by a doctor then that might help to persuade them to refund too.
If you are going to re-book at a later date maybe you could ask about crediting you for the none taken flights? I know here if you change anything on an airline reservation they find a way to charge you! Good luck:heart: