This is one case where the loss of DL as a partner really hurts. While AA is still a partner, they do have one flight a day through Dallas in the morning which arrives at 115PM. You can see if that has award space or if they could confirm on that. Otherwise as Virgin America has no flights to ATL, your only option is to take an AS flight or get the points refunded.
There is no chance that AS will return the points to SPG. Just keep in mind for the future if you transfer points to a carrier that has very limited service at the departure or arrival airport for a booking several months in advance, you may be in trouble.