payment

If you had set it to free before your expiration date it would not have tried to charge you again. You manually downgraded on August 25 but then signup up again for the Pro level on September 3. The subscription renewed on October 3 but your the charge was denied. The Stripe subscription system we use automatically tries to do the charge a few more times since you didn't actually downgrade your subscription yourself it is assumed to be a mistake or card issue. If you want the charges to stop you need to set your level back to free on your own before the charge would have happened. There are only 2 or 3 retries after the original charge when it fails.