Absa personal loans

Good day, Hope you can assist urgently,I called the personal loans department on the 05/10 wanting the settlement amount for the loan account, they told me to pay the amount that was on my statement which was including the interest and I paid it same day. Why did I pay the interest as well but I paid off the account 3 months earlier? I have been trying to call the department since then to close the account with no luck. Can someone call me to close this account and update my information. My statement is still saying my next installment is on the 25/10? Why is it still saying that when my account should be on 0 balance?