It's right in the first few lines of Keystones RV Official Mission Statement...
Build a quality RV loaded with features priced thousands less than other RVs on the market.
Most brands say something like made with "the best value", or "finest materials available", or even "high industry standards"...but bragging that they can build and sell them "cheaper" that anyone else speaks volumes!
Sorry for your issues, unfortunately Keystone will really dig in their heels and give you the full silent treatment now...you will hear them say that you didn't give them the opportunity to correct the issues. And ignore you.
I don't know what state you live in (or rather what State you "purchased it in", however some States have VERY aggresive Lemon Laws so contact your State Attorney Generals Office for Solutions.
Best of luck...document EVERYTHING!