08R320CDI

So shortly after purchasing my 2008 r320cdi, the gauge cluster stopped working. (The part with trip, odo, and all the fun stuff) anyway, the dealership replaced it with a used one with fewer miles and now the odo doesn't show. He told me I would likely have to go to MB dealer and have them program the mileage in so it will work.... Anyone hear of this happening, or had this happen? Still very new with Mercedes, just a little iffy about what I'm being told...