Excess Funder Shocker

I have had a car insurance policy with Discovery Insure for 5 years, and for part of that time my fuel cash rewards were being paid into my Excess Funder account.

This Excess Funder account accumulated to approx R4000 (R2000 of which was my own cash rewards contributions) as I never needed to use it.

I recently cancelled my policy due to exorbitant premiums being charged and I am now being told that because of my cancellation the entire Excess Funder is now forfeited!!!!

I understand that half of it belongs to Discovery, but the other half was my personal cash rewards!!! How is it even legal for this portion to be withheld from me??

I expect the full R2000 to be paid back directly to my bank account ASAP!!