Certainly not as terrible as losing a reservation would be, but I called MS today to give DME info for a January trip. There are three different parties in our group so it took a while to relay all the information. As I finished giving the CM the final flights and times, my phone cut off...on my end not hers. I immediately called back, waited 5 minutes to be connected, and checked to make sure my information had been entered and was correct. It was. About 15 minutes later I got a call from the original CM who was calling back to let me know that DME was all set up. SO...yes, they can call back. They have your membership information right in front of them including your phone number (hopefully you're calling from that number.)