Automatically deleting downloaded songs

[Roxond]

Hey, i have the following problem.

I downloaded my playlist and a few others which I created to hear music in the car etc.

After some time those playlists are not anymore downloaded, even tho I didn't pressed the "Download" button. I have to redownload the whole playlists(with about 3000 songs) and the app is getting bigger and bigger. I have to reinstall the app to reset the size of the app. It's annoying because it takes about 2-3 hours to download all the songs. 

I hope you can help me.