How to cancel my plan?

I suggest you to please contact customer support. hope so it will help you

I suggest you to contact Adobe support regarding this. They might help you in this case

Contact Customer Care

To Cancel https://helpx.adobe.com/creative-cloud/help/cancel-membership.html

-or reply #1 in https://forums.adobe.com/thread/2023066 - includes Chat link

You agreed to a one year contract, and there is a fee to cancel early

When you 'click to agree' to the subscription terms while buying a subscription, that means that you really do need to read BEFORE you buy a subscription... https://www.adobe.com/misc/subscription_terms.html

-LOTS of screen pics of the terms https://forums.adobe.com/thread/2589217 in reply #4

Moving to Adobe Creative Cloud​