Xiaomi India — redmi note 4 frequent malfunction

I got my redmi note 4 phone a few months back, and i am having a lot of trouble almost every day.
1. It's showing incorrect contacts, different name is associated with different number.
2. It updates apps and services sometimes automatically, even if i have disables automatic update
3. Screen feature sometimes works, sometimes doesn't
4. Many a times it doesn't play ringtone when phone call is arrived, even if the ringing volume is full.
5. Keypad tones and volume are absolutely unreliable. I'm able to hear the sound and vibration for a moment n next moment its suddenly gone.
6. Calls automatically go on hold thought hearing aid is on.
7. Apps like whatsapp, hike, facebook, gallery are not working well.
8. Phone hangs a lot of times a day. Its very irritating to restart every time.
9. Wifi connection failure is too a frequent issue and i'm sure of wifi device performance. Sometimes, it shows wifi connected signal but no data is received though wifi has excellent signal.