X-trail damaged by dealership

Bought a brand new Nissan X-Trail end June 2015. Have asked them since then to sort out all windows & panels with \acid rain type watermarks"(windscreen back window side windows small windows)ALL windows & panels in between. Eventually 4 MONTHS of begging they said they wanted to replace my car with a brand new car but instead gave me a loan car which had to be taken back next day with technical problems after eventually getting another loan car"