I'm using AWS too. Last couple of months I stopped their services (might re-new it this month) . They didn't billed me. Did you find-out why there are charging

I'm using AWS too. Last couple of months I stopped their services (might re-new it this month) . They didn't billed me. Did you find-out why there are charging you like consumption of ec2 or snapshot etc ? Something running (or ran) without your knowledge? If you think everything is fine. Then may be tell your bank to disapprove any payment request from Amazon with your account?