Poor Quality agents appointed on repairs - 3rd claim with this situation

I'm in the unfortunate situation of having to claim on my policy from MiWay. The admin around my last 3 claims was good, but the service providers they appoint are pathetic. My motorcycle was repaired poorly (parked off for the last year but repaired panels are just falling off by itself), my car was repaired poorly (different colours of paint used), and now another fly by night used to fix a Windscreen. Why can you not use quality approved agents to do your work? On the windscreen, who is MyGlass?? Can we not use a quality approved supplier like PG Glass?? The idea of insurance is to put me back in the same position I was before. I had a quality original windscreen before; it feels like more sub-par quality parts are being ordered from a subpar unknown agent. Feels like I am being cheated!