Unable to Activate After Restore Settings

I suddenly cannot use my iPhoneX, I was told to update my phone using iTunes on my iMac. After I did the update, it still tells me the same message even after my phone has been updated. I tried many times but it still failed. Then I did the restore settings suggested by the instruction. but after I did the restore and the update, a message appeared from iTunes saying "The iPhone could not be activated because the activation information could not be obtained from the device" then now my phone is on the factory setting but once I connect to my wifi, the next page only shows 

"Unable to activate.. An update required to activate your iPhone".. then it also says "Learn more at apple.com/uk/support. But when I checked it has nothing to do with fixing my phone. 

I feel sad because I spent a lot of money on my iPhoneX, then just after a year and two months it became useless. When I brought it to the service center, they said I have to do a one to one replacement but I have to purchase a new iPhone and they have to take the one I have now. Why do I need to spend so much again for the same phone that I only used for a year? And I was told that I can sell the phone to them for S$200. But if I do the one to one replacement they have to take my phone without paying me S$200. Now I'm phoneless and so disappointed with the iPhoneX that I thought was robust and reliable. That's why I didn't mind spending so much for an iPhoneX because I thought it will serve me well in the long run and thought that I can rely on it, but I was proven wrong. 

I hope there's still a way to fix my phone because I really need it.