How to delete downloaded songs but not get rid of them from library

[RedMod613]

I have spotify premium (version 8.4.99) and I'm using on my iPhone6.

I've downloaded some music on it and I've selected the option to have an artist's music not be downloaded since I don't really listen to them while I'm out and about, however it still says it's downloaded in my phone (I can tell because the songs still have the green arrow next to them even though the artist doesn't have it) despite me selecting the option to not have it downloaded. I don't want to get rid of the songs from my library though, just the downloads so it won't take up space in my phone. I thought the only way I could fix the issue was by deleting and then saving the songs, but spotify recently did away with the little "+" and replaced it with a heart. Yes, the heart saves the song, but it also downloads the song and I just want to save the songs. 

Does anyone have any solutions on how to delete the downloads but not the songs from my library?