I also have had the same problem. I could text but not get voice. They changed the sim card and then I could do nothing. It said I had no service. They ordered me a new phone and I just got it a few minutes ago but it says I need a Sim Card to activate it. There is one in it but it isn't being read and it is too late to get help at the store as they are closed. I may need to go back to my S3 Mini, it never failed me.