@barobaromsafi the very first thing to do is to make 100% certain that you have a valid SIM card. You do need to check with your service provider on that. If it is a working card, then the issue could be your card reader. Make sure that you contact your service provider fist and get a replacement or sign up for service. Most commonly it is not the phone but either a bad SIM card or a missing service contract from your service provider.