Dishonesty, Greedy and *******'s

I am so disappointed with the service that i got from Hyundai Germiston. To start with the salesman told me the price of the vehicle and when he did the application he altered with the price and did not bother to send the quotation before putting in the application, i guess thats how they operate. I was then called by the Used car sales manager who then advised me that they can give me R5000 cashback, i took the car with that condition. I requested the manager (Zipho) to use the money for a reverse camera which he told me it will cost me R3500 like usual they fitted the reverse camera and again did not bother to send me the invoice. I have been requesting for the refund of R1500 since from the 3rd of November 2021 until today the 25th of November i haven't received even a penny no communication and i need to contact them every now and then. He then now says he will pay me R1000 i asked what happened to the 500 he now says the camera is R3600 and that R400 is for VAT question is why was i told that it was R3500? Why was i not told that the price changed then i could have opted for other options? The manager is so rude and can't even address me in a respectful manner. I regret the day i even thought of interacting with that dealership.