Did they remove the bonnet for painting? If so was the paint oven baked after? Important because if not, the paint shouldn't be touched, and definitely not waxed for a good couple of weeks, longer in this cold weather.
Paintwork on new cars is baked in an oven at a high temperature, something you can't do when the car is fitted out with interior, plastics etc. When a panel or even a car is repainted then all they can do is put infra red lamps on to help the paint flash off. The paint will take several weeks to fully cure during which time is shouldn't be polished or waxed. Sounds to me that they didn't get a great finish out of the gun and have flatted and polished too early!