24-02-2014 04:15 PM
24-02-2014 04:24 PM - edited 24-02-2014 04:36 PM
You'll need to log a support request to get 48 to look into this for you and see how/where your data was being used up.
You might also be able to monitor data usage on your phone if iOS has some sort of data meter built in or via an app. There may even be apps that can tell you which apps are using most data.
Hope this helps.
Edit: bear in mind that using the phone for a hotspot with something like a tablet/laptop/PC connected may use lots more data than just for the apps that you are actively using (e.g. Facebook, email) as there can be a lot of automatic background traffic as well.