You'll either have to:
A. Revert to 8.1
B. Use a carrier app if available.
C. Check data usage via SMS if the carrier offers it.
D. turn things off, hope for the best.
Check out "Mobile Data Notifier" for Windows Phone http://www.windowsphone.com/s?appid=0ec1c91d-30aa-497c-a1fb-8dc3e2a0575a
It only notifies me of mobile data I cannot set my data like I can in data sense. But a great idea though.
Yep no 3rd party app has privileges to actually change your phone connectivity features, including limiting your mobile data. But a reminder is not bad I guess.
Yeah, and this is a problem I have. The Storage Sense tile works (and flips) works just like it did in 8.1, but the data tile is broken. The text is way too small and it isn't live. How could the W10M team done one but not the other???BUT, it's not a live tileHowever, it *IS* a quick click on the tile to see your current remaining balance etc. SO not bad...