You have to get some new quotes from other companies. Being competitive,the rates have changed. When the lady at my former insurance asked rudely "what do you need 2 vehicles for?" , I started shopping. Then in the office I told her I was cancelling the next day. "Why???" in front of others in the waiting area, I had the last laugh when I got to say"because for the same coverage, Geico is half the price!!" and it was.
Contact the insurance agent and tell her/him that if your rate goes up anymore you will be shopping around for a cheaper policy.