I have been round with Disney and the vendor that sold us the tickets in February 2020 for June 2020. No refund will be granted and everyone says not to worry, just bring the tickets to a ticket booth and they keep the value we paid. That's fine, except how so we make a reservation? I keep asking that question with no answer yet. The Disney agent did suggest we just buy new tickets to make a reservation and keep the other tickets for another time. I see that was suggested to someone else too. Sigh.
Update- After a lot of back and forth, the outside vendor agreed that if I purchased brand new tickets with a new expiration date, they would issue a full refund for the previous tickets. It happened quickly, with no drama once they finally gave in!