Regarding No service issue in Iphone

I’ve complained a case againt Apple to the Department of Consumer Affairs, India because of non-satisfying resolution of my case. My docket number is: 1187864. I have purchased a newly Iphone 8 plus phone on [deleted], after just 13 months of using on [deleted], I've faced "no service" issue in my phone. This problem arised while updating my iphone from iOs 12.1.3 to iOs 12.1.4. I complained to many apple senior executives and they tried to solve this issue by following so many steps but nothing has happened. My Case number is- [deleted]. Then they said to send my phone to the service centre for other testing and they also assured me that if no issues will be found regarding any accidental or physical damages then there might be a chance of replacement without any extra cost. Then I sent my Iphone device to the service centre i.e., Unicorn InfoSolutions Pvt. Ltd., B-9, Shivalik, Malviya Nagar, New Delhi, 110017 on [deleted] and after checking all things they told me that there is neither any accidental or physical damages nor any hardware or software defects. They said, it might be some faults into the logic board & it can't be repaired so you have to replace it with paid cost which would be Rs. 38,000. I want to claim that if there is not accidental or physical damage found then why would I pay this large amount for replacement? They also clearly not saying that what exactly happened with my device. It's really so disgusting because it's not the problem from my side. After paying a large amount for this phone, I really can't expect this with apple. It's really so harassing for me that without knowing exactly what happened with my device, why would I pay them this much large amount for the replacement? If I pay this much money for replacement, then what will I do if this same issue will arise after some months? Because they are giving me just 90 days warranty. If the same problem will be arised after 90 days then what would I do? I am really loosing faith from Apple. I want to add one more thing that this same issue was arised in their Iphone 7 product when Apple started a repair program where they replaced all the apple iphone 7 as well as Iphone 8 product which were facing this same kind of issue with free of cost either that were in warranty or not (visit the link as I mention below). So, I also want to claim that they should do this same repair program for this device also as they did earlier for their other products because this fault is not happened by me but it's a manufacturing defect. https://www.apple.com/support/iphone-7-no-service/ Thank you for your consideration. I look forward to hearing from you.