Do you get email receipts for your subscription purchases? Search for one of them in your email account. In it, the Spotify username you're paying for is shown:
If you see a random number, that's your actual Spotify username, which was assigned automatically to you when you created your account through Facebook. If you see it in your receipt, you need to use the Log In with Facebook button.
You can login to the website with that username to check the status of your subscription, and your receipts.
In there you can cancel if you want to, and delete your payment info.
Hope it helps. :)
osorniosRock Star 22
Help others find this answer and click "Accept as Solution".
If you appreciate my answer, maybe give me a Like.