While you wait to hear from support, you can stop your account from being billed further by removing all existing instances.
To remove an instance with triton CLI, execute triton instance delete <UUID>. That command can remove any instance, including Docker containers. Repeat within each triton profile and every data center to remove all instances.
To remove an instance in the portal, login to your account. Navigate to the Instances list.Click on the instance you wish to remove. From the instance itself, click the "Actions" menu and the dropdown "Destroy Server".
You will be billed for all provisioned instances, including those which are stopped. Only destroying a server will stop billing.