If your data seems to be getting used up very quickly, it could be due to some apps running in the background and using your data to refresh and send you updates on what is happening in the app. You can test if this is the case by turning off background data usage.
To turn off background data usage on Huawei’s running Android’s Marshmallow (6.0 – 6.0.1), go to Settings > Data Usage and tap the menu icon in the top-right corner. A drop-down menu will appear where you can select “Restrict background data”. This will turn it off. If you want to turn it back on the option will read “Allow background data”. With this version of android, you are unable to turn individual apps’ background usage off. In order to do that you will need to upgrade to version 7.0.
On Huawei phones that are running Android’s Nougat (7.0), you can select individual apps for which to turn background data off. This option also allows you to see how much background and foreground data is being used, so you can select the apps that are depleting your data the most.
To do this, go to Settings > Data Usage and then scroll through your apps. When you see the one you want to prevent from using data in the background, select it and turn Background Data on or off by tapping the option. If you want to prevent all apps from background data usage, you will have to do this individually for all of them. Unfortunately, there is currently no option to do it all at once.
Hopefully, this helps you with discovering why your data is being used so quickly and solves the problem. Good luck out there, we wish you a future filled with lots and lots of precious data.