If the payment is an automatic recurring charge for a plan which you initialized, it is not considered unauthorized and you may cancel future payments here: http://soundcloud.com/you/subscriptions
If you notice an unauthorized payment, meaning a payment for a plan that you did not initialize, please check whether any of your accounts have a SoundCloud Go or Pro subscription through the Subscriptions page when you are signed in.
If they do not, then please email our Payments team through the contact button at the bottom of this article. Let us know the cardholder's full name and the last four digits of the card’s number (on rare occasions where we cannot trace the payment, we may require you to provide further details). If the account is a PayPal account, please provide the email associated with the PayPal account.
Still need help? File a ticket.