So far, I haven't received any solution. They said buy 3 get 1 free. As far as I know, that means I have 4 tickets that I can use anytime.
It turns out the 4 tickets have to be used on the same day.
Traveloka didn't provide any notification that they have to be used on the same day.
I've called Traveloka, but as of this writing, there's been no response.
So my bonus just disappeared.
I regret playing at Kidzilla, which is a small place.