Most the apps in Connect IQ Store are developed by other companies and people than Garmin and they like to get paid for what they do.
Uninstall the app you've downloaded.
I think the easiest way is to do it through the Connect IQ app on your phone. Open the app, click your device, click the type of app you've downloaded (watch face, data field, widget etc.), click what you installed and then uninstall.
If it doesn't work you need to supply a little more info so we can help you. Like what you have installed and what you are doing when you try to remove it.
