AB is being charitable by offering to refund its ticket and could have imposed whatever penalties it imposes for cancellations on your fare basis.
The reason for handling service recovery at DUS is that it's entirely possible that the connecting flight is delayed as well and that you would never have needed to be rebooked.
You are out the $1,500. Will be interesting to see if AB actually issues a refund or a credit for use on another trip.
Last edited by Often1; Aug 20, 2013 at 3:28 pm