Hi there! My name is***** am a computer professional with over 15 years of experience with both Mac and Windows computers, phones, tablets, and printers.I see that you been waiting for quite some time for an answer. I'm sorry about that. I will do my best to assist you. Let's start with the most simple possible solution. Please power off your phone. Please leave it off for at least 5 minutes. When you turn it back on, it should automatically check for updated carrier settings (which include the locations of cell towers, etc). If that doesn't do the trick, please let me know the model of the phone and the name of you Cell Service Provider so we can troubleshoot further. If this does solve the problem, would you mind taking a moment to rate my service? You can give your rating by selecting the stars located on the top right of the question page. Thank you!