You certain it is frozen. On ours it seems to go down everytime I start the car [V], at present it is about 2750 miles, which fits in to our mileage - first service due end of August, car done c.7k since September
I'm about 5000 miles off my second service, and the counter has showed the right interval running up to each. Get top within about 300 miles of the service interval and it'll start spouting warnings!! :-(