Flipkart — No resolution for the extended warranty claims

I have purchased Marq AC from flipkart in 2020. Recently, It stopped working and I have raised a claim with one assist, who provided the extended warranty. However, they rejected the claim since the invoice from flipkart has a different serial number. I have contacted flipkart to correct the invoice and they created an Incident (IN[protected]) on Jan 10th 2023. I have been following up with on the same and even today (Feb 8th) the issue stands unresolved. Flipkart support keep saying I was not reachable on the phone number, however, I have given alternative contact number and they have my email address as well. I have contact they flipkart support in twitter, but still the issue is not resolved.