Network Issue

"Thanks for being with Samsung and for sharing your concern.

Let me recommend some steps to further isolate and determine what you are experiencing. Please be aware that device speeds may vary based on multiple outside factors. We would like to suggest you kindly follow the below mention steps to overcome the Issue:-
1) Ensure that network frequency of your device should be selected on Auto-mode.
Menu>Settings> Connections>More Networks> Mobile Networks> Network Mode> Select Auto mode (GSM/WCDMA/LTE).
2) Search for the Network Manually as follows:
Menu> Settings> Connections>More Networks> Mobile Networks> Network Operators> Select Manual Search.
3) You may check by exchanging the SIM in SIM slots.
4) Insert different SIM card in your mobile and check if the issue is resolved or not.
If still issue persists then we would suggest you to once contact with your service provider.

It is very Harassing that My airtel no.not working ..i changed my old sim to new but it shows no service... kindly pls tell me when firmware issue has been resolved