Students and Faculty can cancel their current Creative Cloud memberships (Non-Columbia) here: https://helpx.adobe.com/creative-cloud/help/cancel-membership.html.
If you have issues online then call this number, with this dialogue: “need to cancel my Creative Cloud subscription as it is now provided Columbia College (Chicago)”.
If you are told there will be a charge to do so please call 800-443-8158. Support hours are Monday through Friday, 5 am—7 pm PT.