This kind of thing happens all the time, Now.. Legally, once the dealer has had the RV made (Assuming you bought it new) If you find out the rig is NOT as described in the WRITTEN contract (or in printed ads) you can refuse it and in most cases demand a refund.
If you buy it used.. Generally the rules vary from state to state.
In my case.. I was told I would be getting a Ford V-10 Triton with an Allison Transmission.. (Allisons do not fit well on the Triton, they fit GM engines, Cummins, Detroit Diesel, and a host of others, but not Fords).
I got the Chevy 8.1L Vortec... (Which is the engine I prefer over the Ford so Though I let the salesman know of the error.. I was NOT complaining).
So far I've had one problem with that Vortec (9 years) Rodent damage to ignition primary wiring.... This, of course, is not a brand specific type fault.. Bit of solder and tape and she was good as new (1 hr labor).
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times