Damaged front door

I moved in to newly built house end March 2013, signed 6months guarantee to maintain anything faulty, I am single couldnt take notice of errors , where I found other things at a later stage, because there were lot of things needed to be fixed, leaking garage, faulty garage door, taps, I noticed this year that even front door was faulty where I could find lot of dust all over lounge when wind blows, I noticed who ever was installing door, cut it badly so much that it is smaller than door frame it left a gap at the bottom you can even see outside. I reported this to Msp I was told about the maintance which I signed it was overdue, guarantee expired although I mentioned I concentrated mostly to the garage which I am so anxious even now that its winter time. I almost gave up & planned to buy new door now I fee not let this company leave me like this even the door looks like old door which was used from somewhere else which scratches all I need Msp to come & fix this I need to enjoy the benefits of buying newly built house, I cant let them go as easy as this they might think since I became quiet since their last email,I cant confirm or recall correct date of incident but Msp is aware