404-577-6970 is the number. It's also a Best Western, so you can look them up at BestWestern.com.
For everyone that is booking at the Granada, I really suggest using it only as a back-up reservation, or having a back-up reservation. Renovations are fun things for hotels, but not for conventions that don't have room blocks confirmed. If they don't have the room, or someone stays over their estimated visit, you run the risk of getting booted. We go through it every year with the RI (and they haven't been renovating). Hotels always over book, in the event some people don't show up...especially when they are probably already booked solid this far in advance.