Maybe escalate the interface with the dealership to the owner? He might care more than the sales force about pleasing his customers and not trying to adhere to the profit line.
I don't see how the dealership could take much of a hit on replacing your trailer with an alike model. The factory and dealership have to work out about the $$$, not the customer.
I definitely wouldn't keep what you have. There may be issues with the frame and/or body being out of square and not plumb. That problem could cause more repairs down the road.