Request Billing support to reverse surprise charges during free trail.

Hello.

AWS re:Post is a community forum site.
Although it is possible to advise users regarding problems they may have, they cannot cancel charges.
If you encounter unexpected charges against your AWS account, you should open a case with AWS Support under "Account and billing."
Inquiries under "Account and billing" can be made free of charge.
https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/checklistforunwantedcharges.html

For questions about your AWS bills or to appeal your charges, contact AWS Support to address your inquiries immediately. To get help, see Getting help with your bills and payments. To understand your bills page contents, see Using the Bills page to understand your monthly charges and invoice.

You can contact AWS Support by signing in to your AWS account and opening the URL below.
https://console.aws.amazon.com/support

At AWS re:Post, if you share an image of your AWS account bill, we may be able to advise you on countermeasures.
https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/getting-viewing-bill.html