While you play, BAGH uses mobile data, especially if the games have live components or often updated content. Mobile internet users find that their data consumption accumulates over time. Connecting to Wi-Fi before you start the app is the best way to protect your data.
Closing other background programs might also help you lower usage. Additionally helpful is disabling autoplay and other features that cause the game to run nonstop. Less data consumption results from slower play.
Go to your phone's settings and see under data or app usage to find out how many resources are there at the BAGH site is consuming. This will help you determine how much is being used. Wi-Fi should be used wherever possible for more fluid and more economical gaming.