Cancelled my private lease car order without penalty but broker says Mercedes will charge me.

Snappper1

I successfully cancelled my credit agreement with the lease company within the 14 day cooling off period as per their T&Cs and was told that I wouldn't incur a cancellation fee. The broker emailed me back "However Mercedes will charge a cancellation fee for cancelling the vehicle" I then queried this charge and the broker emailed back "Mercedes the manufacture charge a cancellation fee as we have took an In stock vehicle of them. An in stock vehicle is at a compound which is called over on a transporter to the dealership to be registered and PDI."
Is this correct or are they trying it on? I have no idea how much this charge will be btw until they get back to me. 
I was told by the broker at the start of the order that the vehicle was in high demand and I should move quickly to ensure I secured one. Which leads me to think that they are just trying to get easy money from me and leasing the vehicle to another customer pretty swiftly.
Any thoughts or legal advice on this would be much appreciated.