Upvote:5
Currently many airlines are refusing refunds and offering travel vouchers or re-booking instead, even in cases where they are legally required to give a cash refund.
It will be very difficult to enforce your legal rights here since some governments might actually give legal cover to the airlines (France for example) and are unlikely to enforce existing laws. There has already been filed a class action lawsuit in Canada against Air Canada.
Your best shot is probably to try a charge back with your credit card company.