Nokia India — nokia 150 mobile network is not showing:shows 'no sim card'

I've purchased nokia-150 on the last nov'2018 & it's under warranty.
It's not showing network connection.
I've contacted [protected]@hmdglobal.com so many times. But the only reply is "we have forwarded your concern to our relevant department".

I have complained on 24-sep-2019. Now, it's 21-oct-2019. It's almost 1 month. I didn't get a solution yet.

I don't know where to complain about this worst service practice in this world.