Just a little update.
I've been in contact with Jannie who's been assisting me today and we've managed to get to the bottom of this.
The culprit this time is the iPhone Podcast app. It really screwed me over here and somehow managed to download over 3G. I have it set to "Sync Subscriptions" BUT never "Use Cellular Data" is enabled. I'm thinking it either bugged out or a download started whilst I was on wifi, wifi dropped, and it failed over to 3G and continued downloading.
Whilst I've still got a fat bill to pay, I do at least know what caused this and can safely prevent this from happening again next month. I've disabled syncing subscriptions, so unless I actually want to download a podcast, the app should (hopefully) behave.
I've been in contact with Jannie who's been assisting me today and we've managed to get to the bottom of this.
The culprit this time is the iPhone Podcast app. It really screwed me over here and somehow managed to download over 3G. I have it set to "Sync Subscriptions" BUT never "Use Cellular Data" is enabled. I'm thinking it either bugged out or a download started whilst I was on wifi, wifi dropped, and it failed over to 3G and continued downloading.
Whilst I've still got a fat bill to pay, I do at least know what caused this and can safely prevent this from happening again next month. I've disabled syncing subscriptions, so unless I actually want to download a podcast, the app should (hopefully) behave.