Welcome to Apple Support Communities.
I see that you're having an issue with not being able to remove songs from your iCloud Music Library on your iPhone 7. I would be happy to help point you in the right direction from here. Here's a resource that can help:
Delete songs and videos from your iCloud Music Library
Specifically, try these steps:
If the songs are still appearing on your iPhone afterwards, let us know which iCloud Download icon you are seeing next to the songs. Here's how to view iCloud Music Library icons and status:
Open the Music app and tap Library. Find the song, album, playlist, TV show, or movie that you want to delete, then use 3D Touch or long press the item.
Depending on if you have the item downloaded to your device, you'll see one of these options:
- If you haven't downloaded the item to your device, tap "Delete from Library" to delete the item from iCloud Music Library.
- If the item is downloaded to your device, tap Remove. Then tap Remove Downloads to remove the item only from your device, or tap "Delete from Library" to delete the item from iCloud Music Library.
If you want to see only content that you downloaded to your device, follow these steps:
Tap Library > Downloaded Music. A message that says "Showing only music on this [device]" appears at the top of the screen. Tap Library in the upper-left corner to go back to your full library.
About iCloud Music Library icons and status