Apple India — complaint for iphone 7 issues

I purchased iphone 7 in januray 2017. It worked fine for 1 year exact. It stopped working after that showing an error " update your phone in order to activate.
I showed it in authorized service center of iphone. They diagnosed the issue and asked for 30, 000 inr to replace the phone. As they do not resolve hardware issues, they said.

I have visited many stores for the resolution without paying this huge amount. But iphone team seems not to help in any case. It is 2nd time this phone has crashed working. And there seem to be some manufacturing defect as discussed with the other iphone users.

I need to complaint for their irresponsible behavior for such an expensive product. It is totally frustrating and dis satisfactory.

Thanks
Akriti