50% increase in car insurance by AON

I joined AON in 2014 at a premium of 2600. I had the misfortune of being in 2 car accidents last year...pure accidents - my wife hits a piece of metal pipe in the road and the bumper got pulled off and I hit a parked car in a parking lot becasue the back end was sticking out over the line...not in what I would describe as being a bad risk, just accidents for which you are already paying the insurance company to cover. AON knocked the premium up to 3000 in November 2014 - thats more than 15 perccent - I am sure this was because of the claims but I can live with this (altho this is the risk they accepted to insure us) However, now they are increasing the policy again to almost 4000 rand. On top of which they have also doubled the excess from 3000 to 6000 rand.. they state its an additional excess (on top of the existing excess???). So its a 50% hike and double excess. I understand they need to make a profit but this is quite unfair to have 3 increases within 1 year. So although the service has been good from AON staff, I just cannot stay with the company because the increase of 50% is simply unaffordable. We tried to complain to AON, they refused to listen to us.