KSFE — interest charged for 10 months upto 1.6.2018 after loan closed fully on 19.8.2017.

I had taken a rcl loan from ksfe vattiyoorkave branch and closed on 19.8.2017 before 10 months of the due date of closing. Ksfe people took interest @rs. 1319/- for the 10 months which is after the closing date i. E. They took interest upto 01.06.2018. I am requested the branch manger to return the amount which had taken from me as interest for these 10 months but they refused to return the money.
I closed my loan before due date for saving the interest. So it is requested that kindly do the needful to return my money which ksfe took from me as interest for 10 months after closing of loan amount fully.