We buy cars- windscreen replacement

I bought a car from Silverlakes 2nd November. Overall thanks to Rob Pretorius and Elmarie Brits for good service. The reason for my low rating is that "We buy cars" use "FCD Autoglazing and Aluminium" to replace windscreens. Everything came to a standstill when they had to replace the windscreen. Rob waited for them from Monday the 8th, but they were full of excuses. By the 9th Nov - late afternoon I phoned FCD and again lots of excuses of why it takes them 2 days to NOT fit the windscreen. The guy then promised me that they will fit the windscreen before closing time the same day. When I phoned early morning on the 10th Nov I had to discover that this was not done and had to phone them again. At long last, it was done and I received the car late afternoon. This weekend I discovered a huge "gap" on the outside between the windscreen and what seems to be the rubber strip at the bottom of the window, a plastic piece in the corner also came loose. I now have to refit the windscreen but for sure are not taking it back to FCD to be fitted - a total waste of time.