Firstly, check to see if you've load aka trade in 2 of each item. Then make sure you completed the progress bar by filling up various items. You need to complete both of these 2 tasks within 4 hours in order to get one ticket. Otherwise, the balloon will depart and you'll leave without any ticket.
Note: If you've completed both of the 2 tasks, but the balloon didn't depart. You can try this method, force-close the game and restart it again. Sometime there's a sync issue between your game and the server. Once the game restarted, check the balloon and you may notice one of the progress bar is not fully filled up due to the sync issue. So fill it up again and you're ready to go! Hope this helps!