how to remove bill on aws account

Hello.

If you encounter unexpected AWS charges, you should open a case with AWS Support under "Account and billing".
Inquiries under "Account and billing" can be made free of charge.
There is no guarantee that you will receive a refund, but if you explain the situation thoroughly, they should be able to accommodate you.
https://docs.aws.amazon.com/awssupport/latest/user/case-management.html
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 inquire from the URL below.
https://console.aws.amazon.com/support