Lava Mobiles — lava z 80

The is a brightness problem in all z80 i have seen. The problem is that even if we turn off the automatic brightness and brought the brightness to the lowest level then put a flash light on mobile then a magic will happen the brightness will adjusted automatically. I have visited the service center even if they are authorized by lava they were unable to solve the problem because it is problem of even z80 mobile so they said it might be a feature of the mobile phone. I want company to solve this problem or replace my mobile by any other model if company has any other better product i don't think lava has any other better product because i have visited service center i have speak to customer care. Till now nothing has been done to solve this issue i had purchased z80 on 19-apr-2018