I get charged for an account that I have deemed deleted.

Yes. Let me copy and paste the message below:

To whom it may concern,

This e-mail confirms that the Amazon Web Services account associated with account ID y is permanently closed and cannot be reopened. Any content remaining in this account is inaccessible and will be erased.

Sincerely, Amazon Web Services

Note that this is an account ID y, not x.

So account Y had me@gmail.com before it was deleted. Now you also have another account X that has me@gmail.com. But you are not able to log into either Y and X. Did I understand the situation correctly?

Yes. I know I can't login into account Y, b/c it is gone. But X I just can't.

When I tried to login with me@gmail.com as a root user, I get a message below:

"There was an error An Aws account with that sign-in information does not exist. Try again or create a new account."

The charge comes in something like this:

Email title: AWS Budgets: My Monthly Cost Budget has exceeded your alert threshold

Content: AWS Budget Notification AWS Account x

Dear Aws Customer, You requested that we alert you when the actual cost associated with your My Monthly Cost Budget budget exceeds $xx.xx for the current month. The month actual cost associated with this budget is $x.xx. You can find additional details below and by accessing the AWS Budgets dashboard.

========================================================================== Now, I get another email with exact same wording + saying that it is forecasted cost.

To add more context, I did receive an email awhile ago about account y has some charges which I've paid off. I had no other information about account x in my email inbox (me@gmail.com), other than monthly email about AWS Budget Notification.