There have been reports of folks receiving ticket refunds - and I think it's exactly the type of situation you have. WDW is trying to work with people. So I think it's definitely worth a call to ask for a refund, explaining that you are unable to visit before September. At worst, the value will be retained as credit towards a future ticket, but I understand your preference for a refund at this time.
Just pointing out the bolded is not accurate. Most tickets are date-based, with a specified "start date" and the expiration date corresponds to that start date as well as the number of entries.