Hertz rental company are *******

Good day, I had done an online booking in December 2021 for travel during tye festive season as i had an accident with my car a few days prior.Upon booking online all was fine but once I arrived @ Hertz Rent a Car at OR Thambo airport, I was told that I was not allowed to book a vehicle and therefore could not receive the vehicle which was already paid for . The lady @ Hertz could not give a reason as to why I was not allowed to hire a vehicle and said that I should email Hertz Customer Relations to get the information... this is ******* I received this reply from Hertz Customer Relations "Unfortunately we have received an alert from another car rental - reason unknown" and nothing further . So how do I get to the bottom of this ? Why cant Hertz furnish me with the information ? I do not hire vehicles regularly and when I do the rental company always holds funds , so I don't understand what is going on and why I cant rent vehicles The service from Hertz was atrocious to say the least and I will not be using their services again!! They don't even give your money back either!! THE REASON FOR MY REVIEW IS THAT I DON'T WANT ANOTHER INNOCENT PERSON TO GET CAUGHT LIKE I DID