Fully refundable won't work at all because that goes back 100% to the original form of payment which in this case will be your FFC with the 6/22 expiration. It's the non refundable ticket (non basic economy) canceled AFTER 24 hours that may generate a new FFC with an expiration 1 year out from booking date (if you're successful in getting that you may want to book closer to June so that you get a full year from whenever you book since if you book now the expiration will be a year from now).