How do I turn off mobile data usage on Samsung galaxy J2

[AC Question]

I have a Samsung galaxy J2, but I only use it at home connected to my wi-fi. However it has been using data from my prepay, which I definitely don't want. I've looked online, but the examples I get are other models of Samsung and just are not applicable to my phone. I've looked everywhere on the phone, but it isn't clear as it seems to be with other Samsung phones. Thank you in advance.

 

[Tim1954]

Does it have a pulldown menu with quicksettings? If yes, pull down and tap mobile data. Otherwise go into settings>data usage>mobile data and toggle it to off. Try that... Also look in wifi settings for "smart network switch" and make sure it's off ..