Nedbank wont cancel optional insurance

I had to take out a policy for insurance on my personal loan, after 3 years of reducing my loan balance, the premium on insurance does not reduce, i tried cancelling the policy and the insurance section keeps putting me through to personal loans, who then put me through to the insurance section. The insurance section says i cant cancel unless i email the administrator and they will help me. I have paid this for years and i want to cancel. When i took the loan they said i could cancel when i needed to.