Pushing will have minimal chances of working. Transavia is one of many airlines that only issues vouchers instead of refunding. Moreover, the German Government said a few days ago that they'll pass a travel-wide law that will regulate the matter (only vouchers to be issued for all "Covid-cancelled" bookings such as hotels, cruises, airlines, etc.) and so far nobody in Brussels has uttered a single word in that matter. Good luck, though. I enjoy seeing optimists these days .