Dealer is refusing to give my car back

I book car for 90 000 service on 24/3/15 & it happens that there was engine problem. I was late for service(97 000) and she told me that my warranty won't cover for me. Then the second option from her manager was that if I pay for service, they will ask Toyota SA to fix the engine. I waited for a month and she come back and said Toyota SA will only pay 30% and the dealer will also pay 30% which I had to pay 40%. The total amount was R15 000. I then asked her to send me the break down, so that I must know how much will it be for me. I waited for this for 2 weeks. I then went back to her and she told me that the quote was removed from the system and she will have to do the new quote. The new quote came with different amount R30 000. I told her that I better tow my car away as the amount is now to high. She told me that I must then pay the amount we agreed for service. I then told her that we only agreed about the amount if Toyota SA is going to fix the car and as it was, I am not supposed to pay for service. She made it clear that if I am not paying for service, I won't get my car. As matter stand, they are refusing to give back my car.