FNB is charging me extra in interest rates, [this is ****************].

Up until today (after months) the below issue has not been resolved. --------- FNB is charging me extra in interest rates, [this is ****************]. Extremely disgruntled, I have a bond with FNB and my original interest rate offer was 10.91% I was then given a discount of 0.25% which should have reduced my interest to 10.66% this never happened I had to send them numerous email (never succeeded), subsequent to this, when I checked by statement I noticed that FNB was actually charging me 11.16% from 10.66% when I asked was told that the Reserve Bank increased the interest by 0.25% basis point, when I did the calculations they don't reconcile.

So FNB is charging me extra, this is ****************.