irishguy28

Both the French and Dutch governments have indicated that, as a measure to support airlines undergoing severe cashflow problems at the moment, they are instructing their national enforcement bodies not to enforce the requirements of EU261/2004 as regards cash refunds when a flight is cancelled. They are allowing a refundable voucher to be issued in place of the requirement to refund the money immediately.

This is in recognition that this is in violation of EC261/2004, but the governments find this preferable than having hundreds of thousands of Euros refunded immediately to passengers, at a time when the airlines have no new cash from new bookings coming in, given that this means that the point where taxpayer money has to be used to bail the airlines out is deferred.

The fact that governments are coming out in favour of such exemptions means that you will really not get anywhere simply appealing to the airlines. You would, instead, have to bring them to court. (In the OP's case, where the flight departs from DUB, an Irish court may come to a quicker/better decision for him/her, should Ireland issue guidance that vouchers cannot be issued where the passenger demands a cash refund - but no such guidance has yet been issued; however, from following discussions regarding Aer Lingus who are issuing vouchers with 10% extra and a 5-year expiry date, if anything, the vouchers issued in Ireland are actually less attractive than what Transavia is offering; the EI vouchers are not refundable)

By the time the court would have come to a ruling, you would already have been able to cash in your voucher.

Transavia's vouchers are refundable after a year: https://www.transavia.com/en-NL/update-coronavirus/This is identical to the system used by AF and KL.

I know this is far from ideal; however, the best you can do now is just to accept the voucher, and to wait.

The chances that AF/KL and/or HV/TO are allowed to fail is unrealistic at this stage.