I have a brand new Samsung S7 with Knox 2.7.1 from Videotron in Quebec and there is no Mobile Data icon in the Quick Settings pull down menu. After talking to Videotron - they said can't be fixed - searching the Internet for a solution - none of them worked. There was one that would have worked but it used a Cellphone Technician software tool that would have voided my warrantee so that was out of the question. Finally on Play Store I tried Wifi/Mobile Data Switch by JTMZ Group and it works. The icon sits on your home page and when touched it brings you directly to the Mobile Data toggle switch in Settings - so you then just touch the title "Mobile data" and the toggle is turned on or off as needed. It does however automatically turn On your Wifi as well. The only thing missing from this program is the icon sitting on your Home Screen should change color when Mobile Data is activated On. But this program is free so I'm still satisfied. I will pay the $2.19 occasionally requested when they include this feature. Other than that this is any easy fix to the annoying omission by some "cellphone service providers".