I'm don't remember how I or why I created this account, but I don't use it, I have a different one, not connected to Facebook, with a different email address. However, I inadvertantly paid for a premium subscription for this account when I had intended to update my billing info on the other account because my card had become compromised and I received a new one. Is there any possibility of merging these accounts, or transferring the subscription, or getting a refund of some sort for the purpose of putting it on the other account? If not I'll probably have to end up eating the $10 but I'd rather not do that.
That won't be a problem, if you get in touch with the customer services team directly using the online contact form they will be able to merge those for you including your subscriptions and playlists if you like.
If you get an automated email reply back directing you to the community or help pages, you need to reply directly to that email (even if its from no-reply) and one of the customer services agents will get back to you as soon as possible.