I was using the downloadable one (Hughes status meter) Now that I know the one on customer support is realtime, I will use that more but it really takes a bit of luck to see crazy usage when not doing anything on the internet. I happened to be 12 hours late narrowing it down to an iphone setting on my daughter's phone (who I allowed via my encrytion setup). I think it is the "wifi assist" setting on the iPhone somehow used 6,2 GB in 12 hours. I wouldn't be surprised if I'm barking up the wrong tree though. I'll see what happens next month and try to catch what is going on.
Yea those pesky mobile devices can get you good. We are definitely looking into finding solutions in notifying excessive usage in a more timely manner. It's something we've seen requested before. Hopefully we'll see something come soon.