Hertz and Rentalcars.Com are useless

I book a car with Hertz through Rentalcars.com. I paid for a full accident waver. They however charged me the full accident deposit of over R17000.00 My booking number was *** After i returned the car they told me i have to wait 7 to 21 days for the money to be returned to me. Not once was I informed of this. They are absolutely useless company I will never hire with them again