Gearbox broke at Audi George

My husband took our S3 audi to Audi in George western cape, we drove there with the vehicle from Swellendam, and asked them to service the vehicle and contact us first before doing anything, we've only budget for the basic service, they contacted us and said the vehicle can't drive because they reset the computer of the car and the electric part of the gearbox broke. They said they haven't driven the vehicle but when we came there the engin was hot, and they also don't take responsibility for the gearbox wich will cost us R53 000