Rates cuts not effected on a Nedbank Homeloan account

In 2013, I obtain a homeloan from Nedbank which I'm grateful for. My loan was approved at 11%, and due to inflation the interest rates escalated to 13% in 2017, subsequently fluctuated between 12.75% and 12.50% between 2***. In 2020 the interest rates have decreased to 9.75% currently. Nedbank Homeloan increased my premiums as interest rates escalated, but never decreased my premiums when the rates decreased. On the 20 March 2020, an email was sent to Nedbank Homeloan, requesting the Nedbank to rectify, but my request was ignored. On the 26 March 2020 I called the Nedbank collections department, I was advised they cannot assist me.

I'm worried if my request is ignored because I'm black. I once called Nedbank trying to obtain a personal loan and requested for the best interest rate, I was told by the consultant I wont qualify for a lower interest rate as it only given to staff members. I asked why they say the interest rate are up to 28%. If they only offer the maximum interest rate to their customers. I went to ABSA I was offered interest rates at 20% and it was reduced to 17%.

I appeal to Nedbank Home Loans to rectify my Homeloan account, and credit my home loan account with the variance, and charge the correct premiums, and not outcast me because I'm black.