Please note that the data usage on your phone is not your real Keepgo balance. It's data warning with 2GB allowance.
To check the data balance, please go to https://myaccount.keepgo.com/, at the Line's managing panel in your account, choose the Line ID and you can see how much data you have left as well as the remaining days.
Meanwhile, you can add the My Account button to the home screen to access it immediately.
Tap on the menu button in your browser when you are in your account and our website and click Add to home screen (instruction may vary depending on the model of your phone).