Hi jaysondio129 ..
Please re-install the app by visiting your phone's App store. (Play Store for Android devices and App Store for ios) Make sure that you are under the Consumer Postpaid and Prepaid accounts.
If still unable to open try to clear data. For Android users, go to Phone Settings > Applications Manager > GServices > choose Clear data. Then register again. For iOS, its only uninstall/install.
Is the app the latest version? If not, please update via Google Play Store or Apple App Store.
Please make sure that your internet connection is stable (Wi-F or 3G). ..