Unfair interest rate on repayment

I took a bond with FNB 2017 where by the house was R417.000 according to my opinion the interest rate of the house is 10percent my monthly installment supposed to be R4000 but am paying R6000 every month and now am not working anymore I've even asked the to reduce my monthly installment they said I must send them the letter that states that I've lost the employment but after that their reply they said they don't do such ,to me is unfair first of all the interest rate is very +- 16.5 percent instead of 10percent am not sure or is cause of skin colour cause some people I purchased the same bond with them they paying 10percent on interest rate I'm willing to pay the house although am not working but the repayment is draining me down cause of inaccurate interest rate