Capitec loan term increased from 84 months to 92

Our loan increased from 84 months to 92 months, bank saying insurance increased, we had a fixed contract and there was not a single day late or no payments, all 16 months paid accordingly, how come they increase months on their own, that's total *******, they say capitec is best bank of south Africa, here they taking our hard worked money just like that, I won't allow this, my wife is gov employee and loan is on her name, we gona take this to court if they make any changes to the loan contract