I had an issue with my odometer after disconnecting the battery it would roll back, the dealer replaced the odometer and was able to order from the factory an odometer with the correct miles. The car stores the miles in the computer.
It is a problem with early 04 models.
The dealer told me the he can not adjusted the miles but can be adjusted from the factory.
The best bet is see if by removing the battery cable it does roll back the odometer if it does replace the odometer.