these are user to user forums. we can't cancel anything and there's no need to request a refund. it should occur automatically.
if you've allowed several days and not seen a refund, use a browser that allows popups and cookies and contact adobe support by clicking here, https://helpx.adobe.com/contact.html?rghtup=autoOpen in the chat field (lower right), type AGENT be patient, it can take quite a while to reach a human
p.s. if you're contacted by anyone (via email or private message), it's much more likely to be a scammer than an adobe representative. ie, double check for an employee badge if contacted in the forums and look for an adobe.com domain in the email address if you click reply to an email. then check again and be very suspicious. any other method of contacting (or offering to contact you) is almost certainly a scam, https://community.adobe.com/t5/using-the-community-discussions/staying-safe-in-the-adobe-support-com....
Refunds are operated automatically, if you cancelled in time. If you didn't cancel in time, you will see the early termination fee. You can check your plans by https://account.adobe.com/plans. If the plan is not visible there, it has been cancelled. Refunds take up to seven busines days.