Update malfunction

My phone was set to automatic updates in which it did. After the last update my phone was fine till it died. All I get now is an apple on the screen or that I need to connect to a pc for it to update again. I brought it to my apple certified repair place. They were unable to complete update so they tried to do full rebooting on the phone. No success. My phone is in great condition, they inspected all aspects of it. No damage I have done could of caused this. Although I do not have apple care for I feel a lil cheated that due to a manufacturing malfunction my phone is junk. I have only had it since Nov. 2018. I’m hoping for some other answers unless I’m truly just out of luck.

Thank you