Bad service, they gave me a wrong part which almost caused an accident

I bought a harp part at Midas Vosloorus branch, I gave the guy who was at till the sample of my car & gave him the year ,name & model of my car, he gave me the harp not knowing that it was the wrong one, I then went with it to press it since it's only way to insert it, On the 3rd day while driving it separated from the bearing since it was of another car model not the one I gave sample for, luckily I was not driving on high speed, I called the Machenic on the road who told me to return it &s how the seller that he gave me the wrong one.

They said they don't have it in stock & I went to other Midas spare in Alberton & they confirmed that I was given the wrong code of harp & gave me the correct one. I brought it to Machenic on road & he fixed it for me. I cleaned the wrong harp which they sold from Vosloorus Midas & I was told that the manager was not available to help me & I left the wrong harp & my contact name & number ask the one who was teller to give it to manager & ask him to phone me, It's been 2 weeks, no call from them, today I called to do follow up & I was told manager is not available &I told the person who answered the call my story, his name is David, he remembered my case & told me that they won't refund me since there is a little scratch while it was pressed & asked again my phone number that he'll tell manager, I think it was not fair that the mistake of their teller or salesman who gave me wrong harp to COST ME,I brought &gave him Sample of Harp & Proven from other Midas they gave me correct Code without a sample. They need not to punish me for their worker who gave me wrong spare part & it almost had caused me an accident if car was in speed, they had to be careful when dealing with car parts, codes, year, models& Sample. Till today this has not been resolved I am being taken up and down.