Flipkart — IMEI number not getting verified while trying to exchange.

Flipkart is returning the error that it doesn’t recognize my phone’s IMEI number when I provided the same for exchange. It shows an error: "IMEI number did not match with selected brand and model". Tried to exchange different devices from different accounts as per the instructions provided by your executive.

I've tried to discuss the matter with two executives but they are saying they can't help and are trying to manipulate the conversation. No one is addressing the issue. I’ve checked online for the authenticity of my phone using my IMEI number and it appears to be clean. I don’t see any other reason why it is not recognized. Amazon accepts the IMEI, and the manufacturer themselves verified the IMEI. What's wrong with Flipkart? Why can't you even create an incident so that someone can look into it? This isn't the first time the issue is happening and I need a solution.