data usage behaviour change

[alaingaudrault]

Recently, my wife's phone indicated that she had run out of mobile data and was cut off. Previously, I believe her service would slow down rather than be turned off. Is this new behaviour? Is there a way to change it back?

Thanks.

[hTideGnow]

HI @alaingaudrault 

it likely some app using data on the background.  Are you using iPhone or Android?  check the usage and try to find out which apps using most the data