Yes indeed.
0-14 days you withdraw from the finance agreement, its as if it never existed. They cannot charge you fees by law.
14+ days you are exiting an agreement with no protection other than reasonableness. Expect typical finance company fees to be applied.
I agree that 'they' (the finance company) can't charge you in this scenario, but what's to stop the dealer effectively withdrawing the dealer contribution as you've cancelled the finance agreement that the contribution was dependent on?