File complaints with the Better Business Bureau, with the Attorney General and mortgage licensing authority for the state in which the property is located. If that's Tennessee, the licensing is through the Tennessee Department of Financial Institutions. The Good Faith Estimate is required to be as close as possible to the final HUD-1. If this was a "retail" loan (made by Franklin American's own Loan Officer, rather than through a broker), there shouldn't be any costs that they can't estimate accurately at application. Also, write to Franklin American's Compliance Officer in their home office and demand a refund of any fee that changed substantially.
If the loan was originated by a broker and closed by Franklin American, you'll have to complain to the broker's home office, and you're less likely to be compensated.