21% Insurance premium increase after 10 months woth them with no history of claims

I'm a Viseker member for almost a year now. I've just received a increase letter. My insurance will increase fro. R778 to R988 per month. This is almost a 21% increase. How is this possible? Inflation sits at 6% and I got a 4% salary increase. Best of all is that I've never claimed before in my life at any insurer, Viseker included. I need someone to contact me ASAP as I'm about to cancel my insurance and move to a new provider. 21% increase in these tough economic times, how do your approve of this?