As is stated in our terms of use, it's not our policy to grant any refunds. That said, we do make exceptions to this from time to time, but if you're unsure about purchasing an annual subscription, it probably makes the most sense to try the free trial, or even a monthly subscription first.
If you'd like to request an exception, you can do so through your subscription settings page. When you cancel your subscription, you should be given the option to submit a refund request. These will be reviewed as received, and you should get a response from a member of our support team within 2 business days, if not earlier.