Complete lack of service

My wife has an Audi A1, just over two years old, on a motor plan, whose Air Conditioner is faulty. This was raised with Audi Sandton in September last year at a service, but was not attended to. She has since taken it back twice for assessments for a warranty claim and to date no-one has contacted her back. In the interim she has to drive to and from the office with no aircon in this heat. She has followed up telephonically with Audi Sandton 3 times since Her last visit, and she is still awaiting a response, unbelievably bad service.