Have you tried pricing out SFO-ATL-AUA-ATL-CLT?
You'd have to orice it as a multi-city itinerary, SFO-AUA and then AUA-CLT.
Otherwise, you'd have two one-ways which would likely price out as two RTs, as AFAIK DL doesn't really do one-way award fares (unless something has changed recently, which is possible considering their rapid-change cycle).
If you are within 24 hours of booking, I think you can cancel and get your miles back with no penalty. Otherwise, as a GM, you'd pay the $150 change fee.