You needed to choose the Monthly plan to cancel without a fee.
If you chose one of the two yearly plans AND you've already used it for more than 2 weeks from the date of subscription, you will have to pay the cancellation fee.
You can try talking to customer support to see if they'll waive the fee. Be prepared to be told 'no'.
Adobe provides support through the Chat function on the contact page or through a phone call. There is no email support.
CHAT: Click the following to contact Adobe customer support staff for help:
You must be signed in with your Adobe ID and allow cookies in your web browser for this to work. Disable any ad, pop-up, or script blockers.
This is the link to the US website. If you are not in the US, the site should redirect to the page appropriate to the region associated with your ID.
Click the chat icon at the bottom right of the page to open a chat session.
If that doesn't work, try this link, which opens a chat window directly:
PHONE: You can also search this page for a regionally appropriate phone number for customer support.