I have encountered this situation several times, and it has taken anywhere from one day to about a week for them to closed. During the process of returning the car, I noticed long queues at the front desk and occasional shortages of available vehicles. They have manually adjusted the return date correctly for me, so it hasn't been a problem. However, if you happen to be overcharged, your only option is to contact customer service. It is advisable to provide evidence such as photos showing the location and time of the vehicle's return to support your request for a correction on the receipt.