iPhone 6 8.0.2 Very High Data Usage!

hi I am having a serious bug with iPhone 6 64GB and ios 8.0.2 and operator H3G Italy. When I use the data connection (only 3g no lte), the consumption of dat is about 500mb per day! Seeing in the consumption data of the individual app (which is equal to the retail traffic of H3G Italy) is an abnormal consumption of the app browser like Safari, Chrome, etc.. (only opera mini with max data reduction works well, with a little data usage, but the connection is under a proxy and is slow). I even noticed that the only open a web page (also in mobile version, such as www.samsung.com) ***** more than 20mb! I also restored the iphone as new and disabled anything that could create problems (connections and use of apps in the background, push notifications, iCloud, etc..) But it appears that the app browsing (and sometimes facebook app and appstore app) consume around 20mb for opening only a website. In one afternoon I consumed all the traffic data weekly of 500mb! Is this normal? It may be a bug in ios 8.0.2 software or hardware (baseband)? The blame isn t of my carrier because consumption thresholds of h3g italy are equal to those found internally by counter apple; iphone 6 really ***** huge amounts of data! I've tried using the iphone 6 8.0.2 of my friend (carrier tim) and has the same anomalous consumption (which another friend with an android phone does not have). Help me apple, I'm desperate and i need a data plan with at least 15GB per month (500mb per day)!