Settlement amount keeps getting increased

I called on 15/12/15 to get a settlement figure , my balance was R 12999.99 however the settlement amount was R 13312.30.I told the consultant that by installment of R 1320.34 was due on the 18/12/15 she said that I would just need to deduct the installment amount from settlement amount which would make the amount R 11991.96 and that I had till 24/12/15 to settlement. I called on 19/12/15 to check if my installment was reflecting on the system & they said yes my balance was R 11679.56 however now the settlement amount was R 12053.93 which includes monthly service fee R 57.00 , insurance R 108.71 & interest R 208.66. I asked the supervisor to listen to the recording from 15/12/15& get back to me. I have not received a call as yet but each time I call to speak to the supervisor the settlement amount goes up but I am not calling everytime for a settlement amount I want feedback on my query as to why the consultant gave me incorrect information & why am I paying interest & monthly fees etc if I am settling the loan???