I run out of data very fast/I think that someone else may be using my internet.

This may be happening for a number of reasons.  

Watching videos, movies, playing games and downloading big files can use a lot of data in a short space of time.  

Make sure you check how much data you are using on a regular basis. You can do this by logging in to your dashboard.  

If you still think that someone else may be using your data then please change your Wi-Fi password.