I have an Iphone 7 and for some reason it says "No SIM" in the upper left corner. The SIM card is still in place. Can I get a new SIM card from a retailer or the apple store?
Sorry to hear that, avv. Let's do some investigating. Did you try removing the SIM card, clean it with a piece of cloth, and put it back in? Remember to turn the phone off while you do this.