Windows 8 is designed to work "in the Cloud" and therefore is going to pull data on an ongoing basis. Microsoft never figured on things like broadband hotspots that have a maximum data limit or cost you $$$ or drop your connection speed if you pass the max for data. They pushed this out with no true understanding of the market other than to appeal to teens with Iphones to draw them to Win 8 phones (lots of luck, MS). Businesses want nothing to do with Win 8 and most serious pc users are not fooled by MS's hype.
Simple solution - roll back to or install Windows 7 and you can then control what data the laptop accesses. The add ons to over-ride the Win 8 App tile screen may only mask it and the data will still be pulled by the app tiles under the add on.