Power to ya!

I pay for unlimited data from Sprint and use it.   

“The only app I downloaded was the face book app and that thing seemed to take up 181 megs on its own which seems just unbelievably high for just an app. ”

That’s odd, I would have thought it would be a universal app, and the one on my 4S is 30mb (and theres no reason it should be bigger on a 5). I only ever download apps when I’m connected via wireless though, as they do vary in size quite a bit – some ported games can be a good few hundred megs.

Location services will use data, but they should use hardly anything, just a few kb’s here and there.

256mb over night, when not using the device, sounds like it has to be doing something unusual. My data package ignores a few things like web browsing and emails, but if my passage usage was that high id burn through my months allowance in a couple days. Literally.

A good tip for when you’re sleeping though is to use Airplane mode, assuming you don’t need to receive calls when you’re asleep. It will kill all connections and save you a chunk of battery – good practice considering you’re asleep anyway.

For what it’s worth I just checked my mobile usage (i.e. data that’s carried over 3G) and it totals 724mb downloaded – and that’s since I bought the phone, nearly a year ago.

Have you checked the data usage on your actual phone to make sure they haven’t made an error at their end?

I can’t think of any way to use that much data without you knowing about it.  

Although not to accuse you of the same, I have heard some ridiculous stories of people burning through data and then complaining to their providers because they haven’t ‘downloaded’ anything. “Nope, no downloading, just watched a view movies, updated all my software, checked my email every 2 minutes, used the phone as a GPS etc. just normal stuff – so where has my data allowance gone!!”