Unhappy customer

On 24 June 2017 I purchased an engine at above mentioned supplier. When i made the purchase the salesman (Brian) assured me that this engine was in good condition and will solve my car problems. The Opel Zafira's parts are imported and out of desperation I bought it for R17 500. The engine was fitted within the week of purchase ( as the invoice clearly states), to my disappointment it did not work. I was advised by Brian to bring in the Zafira with the engine still in it, so that they can have a look. We made arrangements and i took the vehicle the following week (02 August 2017) as i had to book a trailer to transport the vehicle to Cape Town. I phoned Brian on several occassions regarding feedback on any progress, he explained that he is awaiting feedback from the company that is currently working on the vehicle. On 21 August 2017, Brian requested the following : Coolant tamp sensor, Ambian temp sensor, EGR valve, Camshaft sensor and a swirl flat position sensor as the company that is working on the vehicle is requesting it. I informed Brian that I would like to fetch my vehicle if they are unable to fix the problem. At this stage i was fedup, i suggested that they refund me with an amount of R14 000 and keep the R3 500 for the "effort". Since 08 September 2017 Brian kept on saying that he is waiting for the boss to come in so that he can request the refund. The refund was denied. Today (04 October 2017), Brian phoned and said that my vehicle is with then, i can fetch it and settle a balance of R700 for the tests they performed on the vehicle. The vehicle is still not up and running. I am very disappointed in the way this company is doing business. I just want my R14 000 so that i can recover from this utterly bad experience and start fresh in finding an engine and dealing with businesses with the proper business s****s.