We were given a parking ticket that had both North AND South Parking on it. We found out later that when they run out of paper for one of the parking areas they will use North Parking Paper Slips for South Parking. We don't fly often so we were confused. I asked Delta Employees Willis & Kierras for help. After examining the ticket for a bit they sent us to North Parking which was the wrong parking garage. We spent over an hour looking in the wrong garage after a long flight and trip. There is nobody there to help. A gentleman cleaning the garage noticed we were having issues and asked if he could help us. He asked me to hold up the ticket and immediately knew we were in the wrong garage. He gave us detailed instructions on exactly where to go and how to get there. We found the car within 5 minutes.