If you do get charged (which is likely if you subscribed), you will need to get in touch with the customer services team directly using the online contact form and request a refund from them. Be sure not to sign in and listen to music, otherwise you might not qualify.
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.
I am cancelling my account, the company where my husband works is closing its doors. Besides when I could no longer get the music I wanted because Spotify decided to concentrate on Streaming Radio I decided that I could get free Streaming Radio on the internet for nothing. Sorry to say good-bye but those are the breaks.