I was given a non-competitive quote

I first Insured my car with Hollard in 2011 at retail value. Now, 4 years later, after only claiming for a windscreen since 2011, I call them for a policy review. I told them I have moved to a more secure area, I am 4 years older and want to insure my car at market value. Their new quote was R600 higher, which they could not explain. Is this a case of wanting to pass the risk to another insurer?