I would suggest a telephone call first to the insurance company. I had a similar thing happen with my insurance company, and discovered that in their system, the zip code had been divided up and recategorized, putting me into a high crime area. This event was very peculiar since I live in a very nice neighborhood and I'm no where near any questionable area. My zip code is the largest in the city. Somehow they messed things up on their side.

The end result, my agent manually adjusts my charges every year after my phone call to "fix it".