Additional excess added to policy with no explanation or notification

I recently changed a vehicle on my policy and noticed a single-vehicle additional excess had been added to my policy I queried it and was told it has always been applicable, I backtracked my policies and realised it has not always been there but was sneaked in when I had called in to change a vehicle. My frustration is that it was never communicated but just sneaked in, A miway manager has said this is a standard procedure as changes are communicated via policies but I disagree global changes have always been communicated via a letter that accompanies the updated documents. Am I really expected to read a policy document every time I change a vehicle or an address just in case some other excess is sneaked in???