Has anyone changed the designation of their home, like from a condo to a town home, PUD?

We had purchased a house in N. Cali that was advertised as a attached single family but when it was time to process the loans we discovered it was actually a condo. After the whole economic meltdown, the loan rules are much stricter and as a result we have to pay a higher interest rate since it's designated as a condo. Now, we want to refinance with a lower interest but again are running into the same prob, that our house is designated as a condo. But technically our house is a duplex, nothing on top or below us, no HOA fees, etc. Our loan officer suggested that we change the designation with the planning dept. We went and tried to no avail. Does anyone have any experience or advice on this?