Recurring charges from Cloudwatch

Hello.

Are there no log outputs or alarms set in CloudWatch?
If you set up other custom metrics, you will be charged a fee.
When you look at your bill, you should be able to see which CloudWatch features you're being charged for.
https://aws.amazon.com/cloudwatch/pricing/?nc1=h_ls

To stop billing, you first need to identify which CloudWatch feature is causing the billing.
Once you have identified the problem, you can delete alarms, logs, etc. and the charges should stop.