IDFC Bank — Issue regarding Flipkart Pay Later bill payment

I am using Flipkart Pay Later account, that is backed by IDFC First Bank.
For the month of March 2022, my bill payment was marked as Late Payment and that impacted my credit score heavily. Although I have paid the bill on 1st April (The bill payment timeline is 1st to 5th of next month).
That is NOT a late payment.
The technical error from Flipkart/IDFC Bank's end costed me my credit score.
Since last 1 month I have been trying to reach Flipkart, IDFC, Credit Bureau to resolved the issue so that my credit score gets rectified.
But I have not got any support yet.
Please help me to resolve the issue.