Not receiving data usage notifications

Since the start of my contact I have been in contact with Neotel to ask for some kind of Notification as to how much data I use and have left. Beginning of the year I got a huge bill because I went over my limit. I contacted them and asked again to please assist as I'm still not receiving notifications and there is no way to check. Still I don't get anything. I don't want to update software as I don't know how much data I have left. I really don't want another high bill again....