Worst Dealership Experience - Unreasonable and not Transparent

Tried buying a car from Wingfield Goodwood, against my better judgement, after having a bad experience with the Kuilsriver branch a few years ago. Test drove the vehicle, was happy and finance was approved. What was also nice is that the vehicle is still under warranty with the manufacturer and had an active service plan for peace of mind. At this point you would think the deal is done until I saw the final invoice. I was being charged plus/minus an extra R30K. One of the items was their ‘optional’ warranty which I then enquired about and said I did not want because it is optional, and the vehicle is under warranty with the manufacturer which I was planning to extend. But according to the Finance person the Dealer Principal is not willing to sell the vehicle without the ‘Optional’ warranty. I then told the finance person but then it is not optional and should have been noted in the advertised selling price. To which I quickly was corrected and told, no it is optional, but the Dealer Principal will only sell the vehicle without the warranty. At this point I was very confused and knew I was making a huge mistake dealing with Wingfield Motors again. This was just an extra way to make money because the so-called optional warranty is in-house warranty with Wingfield. Then to add insult to injury, they had the audacity to add Gap Cover to the invoice as well to cover their in-house warranty. This is not even mentioning their admin, licence and registration fees, which was about R7K, but I will not go into much detail as this is always up for debate. Also, a noteworthy point is to do your own background checks if you ever consider a vehicle from Wingfield. When I did a background check with the manufacturer, I was told that the vehicle missed a few services, yet I was shown a service book that was up to date. The vehicle also had an engine replacement under warranty about a month ago. Which is why I was not too concerned about the missed services. But it would have been nice if this was communicated to me. I was only informed once I brought it up. So my opinion, I will not do business with Wingfield Motors again. The Goodwood Dealer Principal is totally unreasonable. I will stick to the more reputable car dealerships.