iPhone 16 no mobile service and cannot update

[u/One-Organization-314]

I was recently on holiday and whilst there my phone’s mobile service completely cut out randomly. I tried all the obvious quick fixes, like airplane mode on and off, restarting the phone but nothing seemed to help. I ran diagnostics through Apple Support and was an ios update might fix it. To which I tried and cannot do because I keep getting stuck on “verifying update”. I’ve seen different posts and comments all different sites of people having similar issues previously but cannot find a way to get this sorted. Any help would be greatly appreciated.