incompetence

i have a loan with standard bank fist i took 20 000 and i went back to the branch i requested the loan to be added by another 20 000 which the total amount it will be R40000. now when i check how much am i still owing it shows R40000 and every month R1200.00 is been taken from my acc for the period of 4years but the loan is not decreasing when i check my statement is shows that i have an overdraft which i did not request that . when i go to the branch i get attitude where is my R1200 going that i have been paying every month . i had an overdraft with you and i have settled it and it doesn't make sense how can i take an overdraft again this is a ******* i want solution to this immediately or else am taking this high because the loan is going nowhere this is the 4th year i didn't request an overdraft . please see to resolve this