Should I Try To Appeal A Notice Of Non-renewal Of My Car Insurance?

I've had car insurance with Geico for at least 15 years, with one accident five years ago that wasn't my fault.  Geico was GREAT in handling that claim in which my car was totalled (it involved 6 cars, lawsuits, etc., but GEICO paid nothing--I even got my deductible paid). In January 2010 my boyfriend was bringing the car up from a parking garage and bumped a concrete pillar.  I wouldn't have put in a claim, but in trying to do the right thing he called his insurance agency to try to get it taken care of.  Of course, they explained that my insurance would pay and they would have to notify Geico, so Geico called and I explained the whole thing.  I never claimed it. Over Thanksgiving weekend of 2010 my sister borrowed the car and ran into a post in the exact same spot on the car.  A few weeks ago, realizing I was paying $1600. a year for insurance for a 2005 car now valued at about $10,000, I decided to put in a claim.  The customer service, as always, was wonderful, both over the phone and at the Geico claim center and repair center.  They paid $2100 for the repair, less the $500 deductible. Several days later, though, I got a letter that they weren't renewing my policy!  The reason is "there are two or more lending losses within the last three years," and they cite the two situations I've described. Both incidents happened to be in Toronto, Ontario, CA.  My son goes to college there.  In the latest one, I was out of the country for two months and the car sat in the driveway except for the weekend my sister went up to spend American Thanksgiving with my son. Should I try to talk to GEICO?  Any tips?  If not, any ideas on the best way to proceed--whether to go to an agent or apply for other insurance online? Thanks!