I got charged $600 yesterday for using 2gb of data within the space of a couple of hours. 

I have auto updates turned off for apps.
I have software update only when wifi is on.

I rang 2degrees 3 times and they weren't helpful, blaming me for everything.

I know how much data I use on my phone. They keep telling me that it caused by an app running in the background. Which is not possible no app uses 2gb's of data in a couple of hours.

I managed to get them to waive part of the payment but i still have to pay $80 after being on the phone all morning. I feel i shouldn't pay anything at all.

Anyone had similar problems? or know what could have caused this issue?