Premium adjustments

I am very disappointed with Momentum, i have been with them for over 10 years for 3 different cars, the last annual increase I was quoted an additional R600 taking my premiums from R1698 to R2242, which obviously I cannot afford. Taking into consideration that I havent put a claim in over 8 years if not more, NO CLAIMS whatsover. My car's value depreciates but the premium keep increasing. When i called them they only decrease the new premium from R2242 to R2000. What happens to the retention of customers. If you dont reduce my claim, I will have no choice but to part ways. You are not the only insurance in South Africa.