I paid monthly but didn’t get moved onto the new terms.
My local dealer has completely put me off another BMW, getting warranty work done was a total ball ache, they made up problems and the prices are just silly.
By changing the price they in effect put you into a new contract with the new T&C's including the new price .That's how I would argue it anyway. Also if you look up the warranty booklet online you will only have access to the new version with the new terms in it.
Doesn't alter the fact the warranty isn't as easy as it should be by any means and the dealers are shocking.