Network service not available
My iphone was repair at apple service centre but after some days i was facing my network service unavailable problem
iPhone 12
Question marked as
No service or searching
Support article: If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support
Go through the various suggestions in the support article above but if they don't help, and your network carrier can't help, then contact Apple Support for further investigation. You should be able to reach them here
Contact - Official Apple Support
or phone numbers
Contact Apple for support and service - Apple Support