You can cancel your monthly subscription online and can contact support for other subscriptions.
Please see this document for information on how to How to cancel your Creative Cloud membership
To contact our support staff, go to the following link: https://helpx.adobe.com/contact.html
(be sure to log in to adobe.com with your Adobe ID first)
Click the Still Need Help? option in the blue area at the bottom, and choose chat. Make sure you are logged in with your Adobe ID, have cookies enabled, and have cleared your cookie cache. If you have issues, try a different browser.