My wife and I have identical phones (Samsung Galaxy S7). On my phone I can go to Settings > Connections > Data usage > Mobile data usage and then click the cog to set up warnings etc. If I follow the exact same procedure on my wife's phone, the cog isn't visible! I had modified the font size for her but even when I revert the font settings to the same as my own phone, the cog is still missing. Is there a particular setting I need to revert to make it show the cog?