Lately when my battery begins to run low, my phone stops receiving text messages. Right now, the messaging app icon tells me I have 8 unread messages but when I go into the app, there's no trace of them. I did receive notifications when my battery was low that my phone was unable to download the text messages and to tap the notification to retry, but then the notification just disappears and there's still no trace of the messages. How can I get these text messages to download??