Repayment and ad hoc difference

3 Month back I took a loan of R100 000 for emergency use. After 2 Month of taking the loan. I realized ii no longer need the mone I should return some of it back and that also will help in terms of mking the payment in time. In our last conversations with one of your service rep they told me tha if I need to return then the money I should use the transfer option and choose ad hoc but ine thimg I have realized the installment amoiny did not change and the number of months changed that kinda surprised me because atleast it would decreased the installment too.

Explain tge ad hoc and repayment optuons for me because I am p***d at this.