DISGUSTING:Legal Action!

I am absolutely and utterly DISGUSTED! with Hertz Cape Town! We reserved and paid for a car yesterday, so that my sister and law could drive 2 hours to get to a nature reserve that closes its gates at 6:30. Just to find out OUR car has been given to someone else and they don't have a car for her!!!!!! This is THEFT and we will be taking legal action! She has been waiting and hour for a car and she won't get into the reserve in time!