If you're having trouble unlocking your in app purchase please try the following steps to attempt to troubleshoot the problem:
1) Ensure that your purchase has gone through: Make sure you have a receipt email from Amazon saying you have purchased the in app product. If you cannot find an email then your purchase has not gone through Amazons system and you should reach out to Amazon support to help diagnose this: http://www.amazon.com/gp/help/customer/display.html
2) Restore your purchase: Sometime game entitlements are not passed correctly. You can automatically restore any purchased made in an app by hitting the "Restore Purchase" button. For GameHouse titles this is always located in the app main menu. By tapping this any purchase you've made in the app will be restored.