I had an HTC one m8 and had playlists and so many songs downloaded with spotify premium. I logged into my new gs7 and it is saying i have premium when i sign in theb i go to music and it says sign up for premium and i have no songs or playlists.
It sounds like you're logging into two different accounts, I did that once before too. Spotify acts like your facebook account and email account are two different spotify accounts. Whatever is saved via facebook won't show up on your email login. That's why it's saying you don't have premium. You can always recover your password online if you signed up with an email instead of facebook.