I'm not entirely clear, but are you saying your home WiFi internet have a daily limit of 475mb? If this is the case, you want to stop background running apps that is using data over WiFi. There are various services that sync over WiFi in the background and they don't have to show up in the recent list.
First go to the iCloud setting screen which is top of the Settings screen. Disable anything you don't want to sync from the phone to iCloud. The big one are Photos, iCloud Backup, and possibly iCloud Drive.
Also right below the iCloud setting is "iTunes & App Store". Turn off Automatic Download for all of the items in the list, especially 'Apps' and 'Updates' which are the main culprits.
Third, disable background running apps. Go to "General" -> "Background App Refresh". Disable all the apps in the list that you don't want to run the background. It's possible some of them might be using data in the background.
Also, if you use the Apple's Podcasts app. Disable "Sync Podcasts" so it don't automatically download new podcasts.