No dealer of RV's is required to perform warranty service. The warranty is with the manufacturer and they alone are obligated to the terms of the warranty. RV dealers perform warranty service to attract and keep customers to make a profit from sales. You neither purchased from them or were likely too based on your own comments. Service work is performed by dealers/service centers to make a profit as well. You were viewed as never being a profit center for them in any way. It was a business decision, not personal.