Twitter takes 2 seconds to setup, do you want to pay $2400 for the tickets! First check on your own to see how much they would be. DL doesn't really free deep discounts for bereavement fares at times you can fine lower on your own.

If you don't want to set up twitter you an keep calling. Also all tix have a 24 hour cancellation grace period, so you can still search for cheaper fares. I know you are stressed, so sorry about your father, but if you do nothing it will cost you $2400 for your tickets.