Poor Service

I recently hired a car from Woodford at Cape Town International Airport. I had booked the car from 1pm on a Wednesday and return at 2pm on the Saturday. I got to Cape Town Airport abit earlier than anticipated, went to Woodford Car Hire gave them my booking reference number and they had told me that my car is ready for me which was around 12:30pm, about 30 minutes earlier than my booking. I was not informed taking the car 30 minutes earlier, I will be charged for a full day. I dropped of the car on Saturday before 2pm as my booking and I get an email later that afternoon saying that I'm charged an extra full day. If I was told at collection that I would be charged for a full day for taking the car 30 minutes earlier, I would have never taken the car and just waited till my original booking time. Called the customer "care", "sorry, that's how our system works", atleast communicate that to your customers.