Worst customer service I EVER had

This is probably the worst customer experience I ever had. My insurance found this company in Brits to replace a window on our car which shattered on Monday due to a stone from another vehicle. My glass Brits phoned me and promised the window will be in Brits at 14:00 on Tuesday, then we'll arrange the replacement. At 14:20 I phoned them to find out what tme will the replacement be done. The lady said she'll find out and phone me back. At 14:21 I phoned again as she hasn't phoned me back. Her answer was that they "forgot to load it". Then she said it will be delivered on Wednesday, I asked what time, she said 08:00??? I told her it is absolutely unacceptable service in today's bad economy and that she promised to phone and I had to phone her again to get an answer. Then her supervisor said they will send a driver to fetch it and they will replace it tonight. Imagine the bad work they will do in the dark as there is no lights in the area (we are at a holiday resort) The latest promise is Wednesday morning latest 09:00????????? Don't know if I trust them to honor the latest promise.