I booked a VinSafari + Wonder combo ticket on the app. During the booking process, I may have pressed twice on the date I wanted to choose (select and deselect), so the system automatically selected the closest date (the next day). Because I couldn't cancel the ticket booking because the system needs at least 2 days before the ticket's operating date to cancel, I asked for support from the 24/7 customer service. Although it was a bit slow (because it was the weekend + late at night), you guys helped me change the ticket. Thank you very much!