Turn Off Download Booster because it uses both WiFi and Data to speed up download times. Also, turn of roaming and if you really want to get down..... turn Data off completely. If rooted..... you can add a Data toggle by using
SqEditor lite v2.1...
Go to Settings Storage/settings.db/system/(Scroll down and find) notification_panel_active_app_list_for_reset/..... add this...
You can also add
Type it exactly as I showed you above..... then save it and reboot. You will now have those toggles available to you. So just turn off Data real easy...... Hope it helps