How to Stop Billing in AWS

I intend to use AWS for free, but I will be charged every month.

This month's (July) issue is "0.0116 per On Demand Linux 2. micro Instance Hour" from "Amazon Elastic Compute Cloud running Linux/UNIX" in "Elastic Compute Cloud".

There was no such claim last month (June), and I have little memory of touching AWS in July.
(If there is any reason, I was charged about 75 yen for the last month, and I think it is possible that this month's bill was charged by manipulating the settings to stop the bill.)

How can I completely stop this month's billing for "0.0116 per On Demand Linux 2. micro Instance Hour" with both "running instance" and "Elastic IP" deleted and with no region error?