We just got my daughter the gabb phone 4 pro. The last two days she has went to school something happens and her phone goes straight to voicemail and her texts don't go through. It is like the device is off, but its not. I know at one point she didn't have service. She came home and I tried calling again and it went straight to voicemail again. We shut it off and then after it comes back on it works. This shouldn't be happening. What is going on? Is there a setting we need to change?