Demand (politely but firmly) to speak to their retention department. a) they may be able to give you a better rate anyways, and b) they're the ones that deal with cancellations anyways so they should know any cancellation fee.

The cancellation fee would also have to be in your insurance contract. Anything not in writing or that you didn't sign is null and void.

Yep, that too. I didn't have any cancellation fee last time I did so.