What happened to quality control?

I'm on my third iFixit display assembly and I'm not happy. The very 1st display I got was a perfect replacement and fit well. Only issue was the front camera went bad so I RMA-ed it and got a new one. #2 wasn't fitting correctly and caused stress which created light bleed. It took a long time to get another replacement because I could tell they hardly believed me another display was bad. But I got #3 and the box I got it in was damaged, the display was missing screws from the back heat shield plate and now it fits even worse to where the display's edge is no longer flush around the phone and it feels like it's too big for the frame. So now I can feel the display edges and it feels just plain cheap, not to mention there's a gap in the top right corner. I know after the first display they ran out of stock, but I'm guessing they must have gotten a bad batch. Now idk what to do. Should I email them a fourth time or is it useless?