Billing without active service

I understand your concern about being charged for Amazon Elastic Compute Cloud (EC2) when you believe you don't have any active services. However, it's important to note that there are several reasons why you might still be incurring charges even if you don't see any running instances:

1. Stopped but not terminated instances: If you have EC2 instances that are stopped but not fully terminated, you may still be charged for the associated EBS (Elastic Block Store) volumes.

2. EBS volumes: Even if an instance is terminated, any detached EBS volumes will continue to incur charges.

3. Snapshots: If you have any EBS snapshots, these are stored separately and will continue to be billed.

4. Elastic IP addresses: If you've allocated Elastic IP addresses but they're not associated with running instances, you'll be charged for them.

5. Data transfer or other EC2-related services: There might be charges for data transfer or other EC2-related services that are still active.

To address this issue and stop future charges, I recommend the following steps:

1. Log into your AWS Management Console.
2. Go to the Billing Dashboard and review your detailed bill for the specific EC2 charges.
3. Check each AWS region for any stopped instances, unattached EBS volumes, snapshots, or Elastic IPs.
4. Terminate any unused instances, delete unnecessary EBS volumes and snapshots, and release any unneeded Elastic IPs.

If you're still unsure about the source of the charges after taking these steps, you may need to contact AWS Support for further assistance. They can provide a more detailed breakdown of your charges and help you identify and remove any resources you're no longer using.

Remember, AWS can't automatically stop charging your card as these resources are considered active until you explicitly remove them. It's important to regularly review your AWS account and clean up any unused resources to avoid unexpected charges.
Sources
Charged even though not using any services (Elastic Compute Cloud) | AWS re:Post
Being charged, but have no services running? | AWS re:Post
I'm being charged with no active EC2 instances | AWS re:Post

One thing you can quickly try is EC2 Global View which will show all your EC2 resources across all regions https://console.aws.amazon.com/ec2globalview/home#

When you look at your bills in the Billing And Cost Management section of the AWS Console https://console.aws.amazon.com/billing/home#/bills go to the foot of the right-hand pane and expand the Elastic Cloud Compute section to find out more details of it is that is accruing charges.

See also the advice in https://repost.aws/knowledge-center/find-ec2-instance