I had the same issue ordering the Solo + Gimbal + Battery package on Monday of the gimbal not being added to my cart. Called their 800 number and had no issue getting it ordered over the phone with the gimbal added to it at $0.00. Should be here today. My extra battery has not been so fortunate and is coming cross country from Oregon. I got the dreaded severe weather service disruption from UPS, so now they apparently can just deliver it whenever they feel like it. Ordered another gimbal for a backup yesterday, along with the Lowpro DroneGuard CS400, and those should be here today.
Got excited when I saw some 3DR stuff showing up in that "25% off when you buy 3 or more accessories" deal, but the fine print says discount is taken off regular prices. So none of the 3DR stuff applied since it was all on sale.