This is not a test user account 解决办法

1) Uninstall AppSync from Cydia.

2) Uninstall your game or app.

3) Reboot your device.

4) Re-download the game or app from the appstore.

5) Make the in-app purchase.

6) (Optional) you can then reinstall AppSync… but only if you like doing the above five things over and over again.