Unfortunately some Fitbit models are not supported. The supported models are: Fitbit One, Fitbit Ultra, Fitbit Force, Fitbit Flex and Fitbit Charge HR. Fitbit Surge and Fitbit Zip are supported but only for a brief time losing it, for they stop emitting signals to save battery. Fitbit Charge is supported but it also stops emitting signals after some time and the signals it emits are not reliable.
Fitbit is constantly updating their devices and adding new ones to their product line. We will add support for these models as soon as they are possible.
We are very sorry to hear that you did not find our app helpful. To get a refund you must ask the Apple Customer Service for it. Here's a guide to help you on how to do that: http://goo.gl/uZoP6y
If you’re having any problem with the app or if you want to drop us a message, you can contact us at firstname.lastname@example.org