Bad bad service from Outsurance bad service

I had my windscreen replaced me n Februar 2018 by National Auto Glass via Outsurance because they advised me that this will be the best for me. With the rain that we had in March my windscreen l aked leavng my poor smelling like a rotten carton of milk. I reported it to Outsurance and they resent National Auto Glass back to me. They removed the fitted windscreen, reglued it back and left. Now i sit with a windscreen that still leaks, doors that wont close properly and a rattle in my dashboard. I went back to the branch that fitted the windscreen and the guy at the branch told me it was normal for a dashboard to rattle! I then made a very ****ed off call to Outsurance and was promised they will sort this out for me. I have also spoken to the warranty manager of National Auto Glass and he too assired me this will be sorted out soonest. Now it is April 2018 and still nothing. I have gone to BMW to get a letter to staye that this windscreen is not the right one and not approved by BMW standards. Today, I again, phoned to find out when my windscreen will be replaced and I'm still waiting for someone to phone me back. I really don't know what to do next.