Waiting on cancer

I currently have a lump on my breast which is growing. I have been to see a specialist and we have found that it is a complicated cyst which if not removed can turn cancerous. My surgeon has sent through a letter of motivation for my surgery however discovery has declined my surgery saying it is not a cancerous lump and therefor its declined. So discovery would be willing to leave the lump in till it turns cancerous and then remove it. Is prevention not a priority? Why do we pay such exorbitant medical aid premiums if we are not going to be given the treatment we require.