I book the original tickets through DL SMS. If I have a problem while I'm on the road, I just call the SMS number in the USA to take care of things. I've done this in BKK for a medical emergency to return to the USA on KE, I've done this in Germany to get my lost bags from AF at MUC...

As long as you have booked through DL and are willing to pay the international phone charges, the SMS folks are great at fixing things around the world.