Hi
The following steps may help:
When looking for the iTunes Store app, keep in mind that you may have moved the icon to a different Home screen and/or moved it into a folder (which may itself contain multiple pages of apps):
- To search for the app, when viewing the Home screen on your iPhone:
- Swipe down on the centre of the screen > in the Search box at the top of the screen, type "itunes" > if the app icon is found and shown, it will also show (to the right of the app icon) the name of any folder that it has been moved to.
- You can also tap on the icon from within the search results to open the app.
Another option if the app has not been removed is to reset your app layout. This removes all folders, restores the original wallpaper and returns the Home screen and all apps to their original layout (third-party apps are listed after built-in apps):
- Go to Settings > General > Reset, then tap Reset Home Screen Layout.
Under iOS 10, you may have removed the app from your iPhone. If so, to add it back, open the App Store app, search for "iTunes Store" and add the app back to your iPhone.
Check whether Restrictions have been enabled on your iPhone for iTunes Store:
- Go to: Settings > General > Restrictions.