Just bought another ASD but its developed a horizontal line across it. Spoke with Apple and looks like they don't have a mail-in repair option for these and I'm a 5 hours drive away from an Apple Store.
Best option they thought would be for me to courier the Display to someone down there who could make an appointment, take it along, get it repaired and send it back.
To their credit, after speaking to a few different people, they agreed to replace it by courier as it's only 3 weeks old. UPS were going to pick up the old one today (they haven't) and once they get it back they'll send a new one out.