Worst Customer Service Ever

Worst customer service ever. I went to this store yesterday and asked for a door mechanism for my car (as ordered on the previous Saturday) and was given a window mechanism and because I do not know these things I got to the person who is supposed to fix my door and he said they gave me the wrong part. When I went back to exchange the part the coloured guy I bought the part from told me about him giving me the correct part and me saying I wanted a window mechanism. If you see in the attached screenshot from whatsapp I specifically asked for a door mechanism and he insisted on charging me a 20% penalty fee as he "gave me what I wanted" and he proceeded to get me a refund minus 20%. Even a picture from Google shows what a door mechanism is. If there was zero stars I would definitely give them zero.