'No Service' iPhone 7

After +3 years of using my iPhone 7, I suddenly got the 'No Service' problem despite my SIM card being inside. My iPhone's model (A1660) is eligible for the Repair Program. So I took it to a licensed Apple service provider and they initially told me that my iPhone is eligible, however, they just had to check that my phone's symptoms fall within the repair program.

To get detailed, the repair program includes phones that had 'Error' written next to 'Cellular' in the settings. Mine did not for some reason. The technician tried updating the phone to the latest software version and had to restore it in order to do that (not enough storage). So, when booting up again, at the famous 'Hello' screen, 'No Service' is still in the top left and after having connected to a Wi-Fi network, the next screen shows 'Unable to Activate'. Under, 'An update is required to activate your iPhone' and finally at the bottom a blue button with 'Shutdown'.

So, I'm now in a situation where I believe my phone is eligible for the repair program but I missed out on a technicality since my phone happened to not display 'Error' even though the problem was essentially the same. And now, my phone is stuck in a loop where it needs to activate in order to update and update in order to activate. If anyone was ever in this same situation or would be able to help me out in some way I would really appreciate it. For now, the phone is useless and bound to be scrapped.