Most dishonest service I have ever experienced

I recently bid for a car on auction having indicated that I will be using finance or need finance for the car. I had approved finance with my bank, the dealer then put conditions now that since its now finance I have to pay them for the tire place to fix faulty tire (they had indicated this as a fault on the vehicle and I was happy to fix it myself once I take delivery of the vehicle).

Then they said it's compulsory for me to pay for servicing the car before the sale is concluded. I was not happy with this and reluctant but eventually paid for service to be done after voicing my objection. Now they bring up that I have to take the warranty before sale is concluded as this is compulsory on their side. I refuse to do this as from what I know warranty is not compulsory on second hand cars. Correct me if I am wrong but I can choose my own warranty after taking ownership of the vehicle. With the repair, service, delivery and registration that I am paying for now it's compounded with this big warranty charge that I have to pay for as well. This is not right but they are threatening to withhold monies I have paid thus far including the auction deposit if I do not give in and conclude the sale with the warranty.

Below is their clause on the webuycars site that they themselves are now breaching, nothing here states warranty is compulsory.

3. What are the terms of a financed auction vehicle? The vehicles sold on the auction are usually sold “as is” without any warranty whatsoever.

If you use bank finance secured through WeBuyCars to bid on a "financeable" vehicle, our standard finance T’s & C’s will apply. WeBuyCars is willing to sell a warranty with the vehicle, giving you peace of mind. Please visit our website for more information.