refund and cancellation of renewed subscription

The dates you wrote indicate an annual plan, not an annual plan with monthly payments

Unfortunately, my knowledge (as another user, not an employee) is that you should have cancelled before the renewal

Nobody here in a public forum can help, you MAY be able to get someone at Adobe to help

This link will go directly to the chat option
https://helpx.adobe.com/contact.html?rghtup=autoOpen

refunds are automatic, if you're entitled to a refund. 

select your plan type (at the top of the page here), https://helpx.adobe.com/manage-account/using/creative-cloud-subscription-terms.html