I had an eCredit for an unused flight from 11/17/11. Original flight cost $975. I canceled the flight before 11/17/11 and was issued $900 eCredit (after the $75 change fee) valid to 10/28/12. I called Delta to ask how a refund would be issued if I booked a refundable ticket with my eCredit. I was told that a refundable ticket could not be purchased with the eCredit. When I checked online it appeared a refundable ticket could be purchased with the eCredit, but there was a notation in the footnotes that any eCredits used to purchase said refundable ticket would not be credited back if ticket was not used. As a result, I did not pursue using a refundable ticket. However, I booked a cheap flight that I do want to take to Florida next March for $191. I was expecting that I would have to book something for the remaining $700+ by midnight tonight, but when I logged onto my skymiles account today I discovered the eCredit with the same number, but the balance now shows up as being issued 10/27/12 (yesterday, when I purchased the FL ticket) AND the expiration date has changed to 10/27/13 so I have a 1 year extension on the balance. I printed out the screen with that info in case the expiration date changes back somehow or the eCredit shows as closed or expired after today.