ZestMoney - False info giving to credit bureau Zestmoney scam

I took a loan (EMI) from zest money last year (**** Nov). For my first payment when I try to pay their payment portal was down and when I called their customer complaint about the same they said to try after * days. Finally, when I made the payment although at that time they did not say anything later found out they reported me for late payment despite my willingness to pay and the only issue was their payment portal was not working.
Secondly, I repaid all my loan (EMI ) on December itself in one go instead of EMI each month problem is this repayment history not reported back to CIBIL so now CIBIL thinks this loan is still active with late payment which is greatly impacting my credit score.
I have called to zest money customer care, written more than *-** mails, raised complaints, waited for * months as per their mail for resolution still not solved. I have proof of all on-time payment closure + email conversation with zest money customer care accepting their fault. Please get me help and resolve this issue.