Robbing vehicle finance theatrics

In 2010 I bought my first car (Mazda 3) financed by Wesbank. The car was initial selling at R116000 but they put some hidden extra charges taking it to R123 000 (I was fine with the charges). I paid a deposit of R12 000, unfortunately my R12 000 deposit was not deducted from the R123 000 capital loan, they first calculated interest, admin fees and credit life insurance, taking the contract loan to R178 000 and then deducted R12 000 taking the loan down to R166 000. I think I was treated unfairly and ****** by Wesbank by not deducting R12 000 from the capital loan. I had R12 000 which means I only needed the bank to borrow me R111000, unfortunately this was not the case as the bank charged me interest, admin fee and credit life insurance even on the R12 000 deposit I paid.