Croma — Unable to connect to any wifi network.

The TV was working fine and suddenly it restarted multiple times and then I found out that the WIFI is not connected. I tried to connect the TV to another WIFI, but it was taking too much time and then eventually gave me the error "Unable to connect. Please try again."
I switched off both the TV and the router. And then after some time opened both. Was able to connect other devices through the Wi-Fi router but the TV was unable to connect.
I then went to TV settings and chose the option to restart it to initial settings. When I was going through each step, and came to network step, it was unable to connect again.

Now I cannot use TV at all. I don't know how this network problem happened and now when I am calling customer care, they are asking me 956 Rs as service charge for technician to arrive and look at the issue. This is totally unacceptable.