High interest rate

Too expensive, now prime interest is 10,50% but their interest on my bond is 11,20%, I put extra of R2600 on my monthly premium, but it doesn't make any difference, I instructed them to put it on capital amount so that it reduces interest and term, non of that is happening, you request a call from them they take ages to call you, if they ever call... I regret using them... need clarity