I have a solution! (I'm exusing myself because I don't know english too well...I hope you will understand my intructions!) :)I had that problem too. So i googled like a 1000 times... I wanted to experiment with my phone and I found out how to disable mobile data tofor some apps... Just go
Go to settings, than mobile data and you haveSettings →Mobile data (you'll see a list of apps that use mobileMobile data (skypelike Skype, viberViber, whatsapp...Whatsapp, and so on) and click→ tap one of them (example vibere.g. Viber) then→ scroll down where it says,, Disable mobile data" andto Disable mobile data or similar... Click there → Tap it and agree to what they say andis mentioned there.
Now you dissabled mobiledisabled Mobile data for viber..Viber. I know that you have so manyYou might be having lots of apps and that is boring but itsthe effort pays off! :) Or justYou may limit mobile data usage to 0...That0
since it works too... :)