Redundant charge of canceled trial plan

If you cancelled the plan correctly, you got an e-mail saying so. If you did not get that e-mail, chances are high, that the plan has not been cancelled correctly. You can check this, by navigating to http://account.adobe.com/plans. If you are still in the 14 days window, you could try to cancel again, and you would get refunded.

If you are not in that window, or if the plan does not show up, or if you need assistance for cancelling, please contact Adobe customer service on this. Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. Pop-up blockers need to be disabled! If the chat window fails to open, or is non-responsive, use a different device to start the interaction.
Support phone numbers may be found here: https://helpx.adobe.com/contact/phone.html. Please note that phone charges may apply.

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)