I signed up for Azure Trial, but I don't use it anymore. However, they are still charging my credit card. I want to unsubscribe but couldn't find a way to do so. I tried to reach customer care also but there was no response.
How can I cancel / close my account?
To cancel your account, login into Azure account portal @ https://account.windowsazure.com/Home/Index. Once you're in there, click on your subscription and you will see an option to cancel your subscription.