Dealership Not Paying up for damaged vehicle engine.

My brother and I bought a Nissan Almera 1.6 from this dealership based in 400 main lawly street lenasia . upon entering the dealership the salesman Nesh welcomed us to the Vehicle we wanted to buy. 1) he offered a test drive , my brother and I Agreed to. My brother insisted on asking the salesman (Nesh) if the vehicle has been in a accident or overheating issues , which he said no overheating or accident damage which I did notice the air-conditioning pump/water pump wining. My brother asked the salesman (Nesh)to take the car out for him to test drive. The salesman then reversed with excessive speed in reverse ,which made the Almera collide with a White Honda Ballade that was parked slightly behind the Almera. We then out of shock just said what now?, which Nesh said don't worry is nothing I'll sort it out. 2) my brother took the vehicle down the road , and the salesman (Nesh) once again assured us that the car is 100%. No overheating , we won't have any problems.As he purchased the vehicle in Kempton Park and its drove to Lenasia fine. My brother and Mesh then sat down and spoke figures, where now my brother is bringing down the price for the damages and and. Nesh didnt offer much discount as the Car was R29.999. My brother had gotten down to R28.700 . which isn't really adding up to the problems I've already picked up before the test drive even. 3)my Brother had then paid over the money via Eft of R28700 and signed a DELIVERY NOTE as a receipt of payment. No spare keys , no books , no services history for this vehicle. Then we depart from the dealership home. Upon reaching Xavier road offramp my brother indicated behind me to stop. I stopped on the side embankment to find this Almera leaking exessive water from the radiator cap on top. We waited for vehicle to cool down. I then called a rollback to collect the car. 4) I paid the rollback cash ,(that my wife had in our savings safe at home )R1200 which they normally charge R2800 for that trip. They did us a favor as we know them personally. 5) I them mentioned this frustrated situation to Nesh and requested a refund on the rollback and I bought a waterpump R400 as he (Nesh) said is making the wining noise. That came to R1600 total which Nesh Refunded only R500 to my Capitec acc. I had called in my mechanic to oversee the car which he insisted The head gasket is faulty. I then had bought a set for the car(headgasket kit) R650 to which my brother covered the cost as well as having the Head reskimmed. R850. Once I had gotten back the head , my mechanic had then said the piston needs new rings abs bearing , so him and I took apart the rest of the engine, removing it completely. We now sit at a place where Nesh refuses to cover cost of the damaged engine, due to the headgasket broken and My brother done have the cash to repair as he bought a cheap car being told that he can drive off and nothing will happen. Now we string with almost R4000 of parts and debts for this car which we day the Salesman Dealership must cover.

Thank you very much.