Apparently I have 2 accounts. One logging in with Facebook where most of my selected music, play list, etc., are. And another account with my email and password. I upgraded my subscription to Premium but I ignore which account this was applied to. Seems that ‘the Facebook account (main account) continues to be FREE and Premium has not being applied to it. How can I fix this situation?
Sorry to hear you've purchased a Premium subscription on the wrong account.
If you have access to both accounts, you can log into the Premium one and search for the second account where your music is. You'll be able to follow all your playlists and friends/artists to continue using the Premium account as usual.
You can even create a playlist with all your saved music on the Free account and then save the music from the playlist on the Premium account.
If you don't want to keep the account where you purchased the subscription, you can cancel the subscription and use the time of Premium you paid for. When the account goes back to Free, you can just close it and resubscribe using the correct account.
All the best.
“Music acts like a magic key, to which the most tightly closed heart opens.” ― Maria Augusta von Trapp