Everytime I open the Spotify app on my mobile it redownloads every song I have, then when I go out and use the app to listen to my music it starts downloading again using mobile data. Even though I'll wait untill it's downloaded all the songs via WiFi then make all songs available offline (little green arrow appears). I haven't had this problem before untill the most recent update. Its very annoying as I use it quite alot on the go (work, gym, car) and it's nearly put me over my data allowance!! Anyone have any ideas as to why this is happening and why I can't listen to my music offline?