Extreme Data Usage Samsung Galaxy Sky

[raunchnroll]

Please Help...I've used Spotify for 3yrs now no problem...I used to play full albums on weekends all month with 3gb data plan,never had problem...Bought a Samsung Galaxy Sky(Straight Talk,all Android phones i had were Straight Talk)with 5gb data plan and have ran out data in 3 weeks,so this last month Spotify used 1.04 gb data,i only played 4 whole albums only on wifi,never used it on 3g...What gives...I have 7 albums i downloaded for offline 7 have no playlists...Thank you for your time...raunchnroll