Bad customer service

Good day my husband was there yesterday to buy injectors for a daewoo matiz 2000, your salesman Abdullah helped him. He also took the old injector with to make sure he gets the right parts, when we got home the injectors didn't worked, it was even worse. Did some research and it turns out that the injectors that was given is for a golf/polo not a daewoo matiz. the number on the injector that was given is also far from the number that is on our injector. Also your invoice states that it is indeed for a golf or polo NOT a matiz. I also spoke to an injector specialist and he recon the paulse of the injector given is not the same. I am gonna attached all my prove and keep it as R1050.00 is alot of money and i don't think it's fair just to say sorry it will work just to get the money and rob the customer. My knowledge tells me if you are not sure what to give ask for a vin number or google.