Hopefully the car rental company has left a sign with instructions or a contact number. In this situation, use the number they have provided and let them know that you have arrived or follow the directions out to the car park where a rental attendant will help you.
If there is no sign, check your booking confirmation email for a contact phone number.
If you still have no luck with making contact, call us at 1300 722 920 and consider heading to the parking area and look for uniformed staff. Don’t be alarmed. It’s not unusual to see unmanned rental desks, but rest assured there’s usually help out in the car park where the rentals are located.