no service, carrier selection not available post replacement of Iphone
Hello I have started receiving this problem after getting a replacement phone from Apple. My original phone had a broken screen, they tried to replace the screen but something went wrong so they gave me a new phone. Set it up correctly and the network worked fine for 1 day and suddenly it says searching and the carrier selection option is no longer their in settings. Went to Apple store and they gave me a new handset. again it works for 4-5 hours and then stops working. My swisscom sim works fine in any other phone. Restored to factory, connected on apple site and deleted my old devices still this issue is their. Please can someone help.
iPhone 6, iOS 9.3.4