I want a Refund!

I really don't understand why I cannot access my downloaded music(OFFLINE) when I'm not using data/wifi on Deezer Music App whereas I pay monthly for it! What is the use of downloading the music when I'm going to spend money on data to access and stream the music I downloaded again? I really wouldn't mind if I was told from the beginning BUT I was not and this is not what I signed my money up for!!! I want my data or money back!