I understand that you are unable to access the Google Play Store on your off-brand tablet and I do apologize for any inconvenience you've experienced in attempting to do so. I don't believe the SlingPlayer for Kindle Fire will work for you and there are no refunds through the Amazon App Store (as far as I know). In order to use SlingPlayer for Android Tablets your device would need to meet the system requirements and have access to the Google Play Store. Again, I'm sorry about any inconvenience.
Here is a link from our product page where you can find the minimum requirements for SlingPlayer:
Hope this helps!
The Sling Moderation Team