Aram.
Two possibilities to consider:
A3 instrument panels are prone to failure, usually with flickering lights or the instruments simply die. I have not heard of such a fault causing the engine to die. The panels can be repaired by specialists at a much lower cost than a new Audi panel.
A defective battery can cause seemingly unrelated electronic problems with, for examples, cruise control, radio, air conditioning etc. Again I have not heard of such a fault causing the engine to die. Even if your battery starts the car easily it does not mean it is in good condition. If it is more than perhaps five years old it would be worth buying a new one. Don't forget to get it coded to the car.