This has a VERY simple fix - get a new insurance company. Most companies slowly raise rates on customers who don't shop around. I'd actually recommend most people get at least one insurance quote at least every other year.

Every time my rates go up by a non-trivial amount I get some quotes from other companies and I'm always able to lower my cost for comparable insurance by at least 20%. I'm paying less for car insurance than I was 10 years ago and I've raised my coverage significantly.

It's really that easy if you don't have any tickets or claims.