It seems that you've just been fobbed off by an unhelpful dealership.As you seem you be happy-ish with the car so far,it might be worth sticking with it for a while.At least until proven otherwise.
Anyway,wouldn't the same info be available via any Sytner dealership network.Oldbury have been quite helpful to me in the past.A personal visit will probably get you a better response.
I don't know where the car that you're looking at is,but the key itself holds vehicle history. and is accessed via a key reader that service departments have on their desks.
If you was to be able to take this into a dealership,the service department may be able to answer a few questions-I did this myself without any issues...