Got this problem about network error. I got excellent signal. I really don't have any idea why my sim card turned out like this. I already followed tips how to retrieve it, like call barring, call forwarding and air plane mode should be turned off. And I don't think my sim card was expired, cz I jz loaded it just this last june 9, 2016 and noticed the problem this june 26. I don't want sim card replacement. What should i do?