Poor service at Jaguar Landrover Bryanston

I took in my car for a service about six weeks ago. As part of the service my sunroof was changed. When I got my car back my windscreen was leaking and letting water into my car which can cause electrical issues. So I took it back to the dealership and they said it is a well know problem with the discovery. They however refused to get me a loan car because it is not a mechanical issue although water can damage the electronics of the car so the car is basically not drivable. This is my second incident with this dealership. Definitely trying a diff dealership with my next service.