Ola Money — Postpaid loan account overdue

Hi
I am using Ola postpaid and recently I’m facing issues. I closed my postpaid account but I got a message from bank that there is an overdue amount which I need to pay. I already contacted Ola and they are very very slow in responding and even I tried twitter also, they simply say that the issue has been transferred to higher end. I want to close my loan account as soon as possible. I don’t want any effect on my cibil score. Please help