Insane Data Usage on iPhone (iOS)

[bevobeats]

For the past 6 months or more, my data usage has spiked incredibly on my iphone. I finally was able to track it to the Spotify app.

The only playlists I use when not on wi-fi are in offline mode (downloaded). To test this, I reset my stats on my phone, play a song from my saved playlist, and the refresh my stats. As it turns out - every time I start a new song in a playist, it adds 20 to 100MB to my data usage. That. is. insane. When I turn cellular off, the song keeps playing (becuase it is downloaded), and the data drain stops. How in the world is this possible. What could possibly be happening in the background???

I'm about to swtich to Apple Music. I'm not going to toggle cellular every time i want the app to work like it should. I also deserve money back for this data drain that has beeg going since like April.

iPhone 6

ios 10.0.2

Thanks for your help in advance.