i did a bit change on the previous one worked on mine :-) change the party boat first than the challenge centre(if you experienced the same problem with it)
1. Go to The Party Boat and check how much time will your reward be delivered.
2. Press Home Button.
3. Double press it and close the App completely
4. Go to Settings and change time to whatever the time that is indicated in your Party Boat. tun off the wifi
5. Open the App. And immediately press Home Button. Dont let the Game load
6. Go back to the App. Then youll see that the reward has arrived. But do not click it. Leave it there.
7Go back to Settings and turn on your WiFi.
8. Go back to settings and change your time as Set Automatic
9. Open the App and click your reward.