I Messed up my cibil score (update)

I posted month back about my messed up cibil and not able get even secured credit cards. After took a report cibil and Experian. I had two unfinished loans

  1. Pending cheque bounce fee from a reputed private finance. Lazy me didn't care to get the no due certificate so did know the loan was not closed due to the cheque bounce fee of the 2 emi's.

  2. Loan from an app.

I paid and closed both loan accounts. It reflected to the cibil account in 30 days. The cibil score has been updated to 771 now. Even after that i couldn't apply for secured credit card to build by report further. Idfc rejected stating internal policy. I applied and got loan from kreditbee and mpockket since this was last option to build by score gradually.

After taking report from experian i came to know that another loan from idfc was written off. It was my Flipkart paylater loan used by a friend 5 years back. I just came to know the due is reflecting in bureau. It was only showing in experian not on CIBIL report.

How do I resolve this issue? Tried contacting idfc customer care, they don't aware of this loan at all. I got an email from creditmantri that they can resolve this contacting bank, get an offer from The bank to pay the due and close the loan. Asking for subscription fee 1875rs to initiate the process. Can I trust them on this. Is there any other options.