You can change a bookings status easily from the Admin page from the booking menu. If you accidentally cancel a booking or a customer changes their mind, Go to the booking in question and then from the left hand menu click into the Admin page you can update the booking status to 'NEW'.
Once on the admin page if you click on the 'Update Booking Status' button you can change it to one of the available options - Choose NEW to .
Boarding Note: if you cancelled a boarding booking and are un-cancelling it you will need to reallocate the pet(s) to runs/rooms for the booking duration of the booking (as the room allocation is removed when a booking is cancelled).