As Blake mentions above, you can contact Data Call for any questions you may have about the Widget, but if you decide you don't want to use it, just remove it from all your Presentations.
You'll only be charged for the Widget if you have purchased it. If you have it in your Presentation, and the trial period is over, it will just show as Trial Expired in your Presentation.
If you have purchased the Widget and you no longer want to use it, you can go to htps://store.risevision.com, go to your Account page, and then cancel that Widget subscription. When you try to add it to your Presentation, it will show as Cancelled.