unreliable new car

I bought a new A3 from audi , the car had to go in for injector repairs twice before It's first service. The car was serviced a month ago and I'm back here at Audi johannesburg with where an igniter coil problem was \fixed". As soon as i drove around the corner at Audi the engine light came on again. As i type this I'm at Audi johannesburg without a car"