Makes no difference, if you haven't done the mileage then you haven't done the mileage. A quick photo proves that easy enough, which I'm sure you took. To be fair, if you didn't get a mileage limit that was sensible for you then that's not their fault: This is exactly why I always go well over the top, as I'd rather spend a bit of money unnecessarily than have a car I couldn't drive sat on the drive. I don't mean that to sound as harsh as I know it does, sorry matey
I've never read an APR in my life, I just figure out if I can pay for it or not