my iphone 14 stopped receiving cellphone signal from the provider. The phone was updated to latest IOS update. Reset the phone to factory settings. After many tries, using wifi, old cellphone or itunes it still wont activate

My iphone 14 (brand new) stopped receiving signal from my service provider. That has happened before, due to updates not installed, but I checked and the IOS updates were up to date. I put the simcard into another phone to check and it received the signal immediately (so not the simcard). I decided to factory reset the phone, but after various tries, using WiFi, Itunes, Old Apple phone - it simply will not activate the phone and gives the UNABLE TO ACTIVATE screen every time.