If you bought your RV on payments from General RV.

I would think that with a loan applications, it would likely be transmitted interstate at some point by electronic means: fax, email, or through the internet to a bank or credit union. If there was fraud involved in altering a contract after the fact without buyer's consent, then that could constitute wire fraud which is a federal crime.

I would contact the Justice Dept. (FBI), especially if similar issues have occurred to multiple buyers.