Floating around the forum is a contact sheet for the warranty folks at FR. I'd suggest digging that up and contacting FR directly (bypassing your dealer). If I were me, I'd layout what happened, why I chose the mobile RV tech and ask for reimbursement. Hopefully they respond favorably. I wouldn't mind not getting back all of the money (service visit, at a minimum), but if you can get most of it back - I'd call it a win.
Turbo makes a good point about their procedures- not having the parts or not having everything you need could be a problem.
Let us know how it goes!