Insurance unfairly cancelled due to staff error

I took out insurance with Discovery in March 2013 after my insurance with Miway was cancelled due to multiple claims. I was entirely upfront with Discovery and disclosed the full history at the time. In Feb 2015 I had my first claim for ****** bicycles with Discovery. I received a call from the Discovery saying that I had not informed them that my insurance with MiWay had been cancelled. They sent a letter to my broker saying that they were cancelling my cover. They then retrieved the call logs from when I took out my cover and found that I had disclosed everything. They said that the whole issue was resolved. I queried the cancellation and was told that the cancellation was issued in error. Now 3 days before the cancellation letter takes effect, my broker informed me that the cover is still in fact cancelled. The apparent reason is because my claims profile was too high when I took out the cover and they would not normally have covered me. This is totally unacceptable as affects my insurance history, when I am not at fault. I insist that Discovery withdraws the cancellation that has been issued unfairly and impacts the likelihood of other companies providing my with insurance.