I agree with Whitepupper. I will (except in very unusual circumstances) Never Turn On Mobile Data Usage. Unfortunately, 3 times this year an update has done so in the background without informing or giving me the option not to. Resulting in all my phone credit being used up in a couple of days without my knowledge or permission. iow, google owes me $150!
I have little money and so use a long life plan which only needs topping up once every six months. I do however have 24/7 access to wifi with unlimited download. Google has made it harder to accidentally disable mobile data, fair enough, but it uses all your mobile credit first before it starts using your unlimited already paid for wifi. They have also made it harder to turn mobile data off completely. It's like they are in cahoots with the telcos to make us spend even more or our hard won money.Apparently at least part of the intention of this update was to save on battery life. What I find drains battery life the most is that even when connected to a network the phone continues to search for other networks in the background indefinitely. There doesn't seam to be a way of stopping it form doing so. The battery lasts about 2 and a half to 3 days with wifi disabled, but only 1 day with it enabled. Being able to disable background wifi network scanning would save a lot of battery life. End of Rant ))
FYI; Codybraithwaite's solution was the only fix which worked for me.
