I have a similar issue, a ticket booked and turned into a voucher (flights were going but as it was TLV I was not going to be allowed entry as a non citizen) at my request the voucher was issued as I bowed to the inevitability. I am unlikely to use it as the winter season flight times are awkward and I am unlikely to want to fly during the summer period.
Has anyone used a voucher, paid extra to turn it into a fully refundable ticket then cancelled to receive the full cash refund?