Canceling an Amazon Prime-based Sundance Now subscription
If you purchased the Sundance Now add-on channel via Amazon Prime, you will need to go into the video subscription settings in your Amazon Prime account to cancel your account.
The instructions are below:
Look under 'Prime Video Channels' to find Sundance Now
Select the 'Prime Video Channels' option and confirm
Once you cancel, the renewal date in your Sundance Now Channel details becomes the end date, and you'll no longer be charged for it each month; however, you can continue to access the Sundance Now Channel through Prime Video up until the end date.