Serious problem with my AMT car.

There is one serious issue with my AMT. Beep sounds and Malfunction indicator lamp suddenly lights on during drive and gearbox fails to shift to neutral.Car stops while braking and fails to start. After switching starter switch off and on many times in some interval makes engine start. My car is 4 month old and i have faced this problem more than 10 times. I took car to service station twice but they failed to diagnose the problem. Will Datsun attend my car? I am heavily worried for it.