Pedí el periodo de prueba, pero me cobró el plan mensual igualmente , cancelé la prueba y no me dió el reembolso

1 - this forum is for Premiere video editing, it has nothing to do with a PDF or an account problem

2 - A refund takes up to 14 days and is automatic if you cancel in no more than 14 days of a trial
After 14 days a trial becomes a subscription and there is no refund when you cancel
To Cancel https://helpx.adobe.com/manage-account/using/cancel-subscription.html

-be sure to keep the verification email you will receive when you cancel

3 - This is a public forum, not Adobe support... other users can't help
This is the new CORRECT way to contact support
https://helpx.adobe.com/contact.html?rghtup=autoOpen

- and enter AGENT in the box asking How can we help you?