Asus India — laptop r558uq

I bought this laptop six month ago and my laptop going into service center after every 2 months (3time problem occurred now it's 4th time), my so much time got wasted.. Asus customer care is not cooperating with me, i think i got defective laptop.

Initially it had
1. Few keys of the keypad were not working
2. Usb was not working
3. Cd-rom problem (It was noisy)
4. Laptop behaved abnormal once put on charge

Every time it took 15-20 approx days to fix the problem so the laptop has been with the service center for near about 1.5 months out of the 6 months.