Poor Service delivery by Mazda

My vehicle has been taken to Lazarus Mazda Centurion with an issue on the vehicle. The vehicle had spent a total of three weeks there and it is still not fixed. They suspect that the fuel injectors might be the issue Mazda South Africa do not want to replace the injectors on a warranty. The last time I was there, the service lady told me there is no active fault code on the car and there is nothing they can do. NOT ACCEPTABLE.