Please keep your posts professional, even if you are angry. Your argumentation will be much more effective.
To cancel your plan, go to https://account.adobe.com/plans, choose the plan you want to cancel, click "manage plan". Cancel answer the questions until the end, and you're done. You will get an E-mail, confirming the cancellation.
If that does not work, contact Adobe customer care and keep a friendly and professional tone, and the agent will help you. If you think that the agent does not behave correctly, ask for a supervisor. If the connection drops, connect again and use the same case number as a starter. If all else fails, post the case number here and someone will analyse the problem and offer a solution.
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)