Quiero la devolución de mi dinero y cancelar el plan

no one can cancel for you.  you need to cancel your own plan.

make sure you're aware of the cancellation terms by selecting your plan type (at the top of the page here), https://helpx.adobe.com/manage-account/using/creative-cloud-subscription-terms.html

and for info on how to cancel your subscription, this page describes the few steps involved, https://helpx.adobe.com/manage-account/using/cancel-subscription.html

after cancelling, double check your account shows what you expect, https://account.adobe.com

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.

if you're unable to follow the steps described, check your account (https://account.adobe.com) for a payment problem. all payment problems must be resolved before cancellation is enabled, https://helpx.adobe.com/manage-account/kb/fix-failed-missed-payment.html