Bad customer service

I went to rear brake disc's. Only to find that they don't have in stock for my car, which they promised to order them for me. I gave the specifications of the car to the sales person. He did order them. He called me and I went to pay for them. I bought together with the rear brake pads. I waited for the old brake pads to worn out so thet I'll fit new brake disc's together with the new brake pads. After driving for some kilometers I started hearing strange or funny noise when applying brakes. Then I checked what was making the funny noise, then I noticed that the disc's they ordered were small in terms of the diameter. It does fit to the shaft. And when I went back to them they said they could not help me. Mind you is the sales person who ordered the wrong parts and now they make it look like I went to the shelf and take the wrong parts.