Hi, this also happened to me last month and when I called the dealer they gave me the number for the AA, all part of the service.
When I took it to the dealer afetr the AA had started it, they advised that the battery was not holding a charge, which they replaced under warranty. The service advisor also said that the car used power when not in use for system monitoring etc and that as a minimum it should be run every couple of weeks. All been fine since, love the car and the way it drives and how it makes me feel