alot of people are not aware that with phones these days even when you are asleep or just not using your devices
the devices are still connecting to the internet and using your allowance slowly because the apps installed are reguarly connecting to the internet to download notification updates or app updates and its making alot of people go over there data allowance without realising it
one way to reduce this from happening is to turn phone off when asleep or place the phone onto Airport mode
you can follow these guides to set up limits on the phones and stop applications from using mobile data if you dont use the applications everyday or when your out of the house as they will only work when connected to WIFI
if its an IPHONE
follow the guide on this website to help reduce it happening again in future
http://9to5mac.com/2013/09/25/ios-7-how-to-monitor-track-your-cellular-data-usage/
on IPHONE in the Cellular/Mobile network option all the apps will have a slider across from there name you can tap the slider to stop the app from being able to use your mobile data and only allow that specific app to work using WIFI when connected.
ANDROID Phones
blog.laptopmag.com/how-to-monitor-data-usage-on-android
if you click on the apps name in the MOBILE NETWORKS menu in settings it show what apps are using alot of data below the graph of data used.
you can press on an app and it will open a info page about the app and at bottom of that page you can tick RESTRICT background download so it will only download on wifi and not use mobile data
