RBL Bank — Unauthorized outstanding raised

Can you please help me on the below situation, I have converted my card into EMI in November 2019 and have connected with customer care to preclose it within a month, he asked me to pay the over due amount which was something around INR 1, 10, 000/-
after paying the amount he said to pay around INR 8, 000/- which was related to interest till date and some charge which i paid off. He confirmed me that all the task and payment have been completed from my end. Now after approx 2 year I see that a bill is being generated with outstanding of 50, 000/- around. after connecting with customer care i came to know that EMI is not closed.

I have been following up through mail and call to customer care from the day bill was generated but no resolution and response so far.
Collection team are calling listening the story but not able to resolve it