RTW awards allow a few "land transit" segments (which basically means you get yourself from D-E on your own). You are allowed free changes, so just call DL.
BTW, there was a recent post (within the last couple weeks) from a DL employee explaining that the RTW desk was still more or less open and how to access it.
Just call.
EDIT: Missed your second post with the east/west issue. I would still try again using the schedule change as a rational.
EDIT2: VN or CI? DL likes to push China Eastern, but they have other ST airlines there.
Last edited by exwannabe; Aug 3, 2015 at 6:26 pm