Originally Posted by
MattFLL
In general… For refundable tickets, you need to cancel the reservation before departure for a full refund to the original form of payment. If you fail to do this, Delta will usually store the value of the refundable ticket as an credit which can be used for a future flight.
It gets converted, but if you call/request they'll refund it. I also believe the request refund page tells you by requesting refund you're agreeing to cancel reservation and request can't be canceled.