IFB Industries — No response & replacement against complaint

Within 2 Months Of Buying IFB 20PG3S Microwave Oven While Cooking there was a flash inside. Some small portion of the cavity was burnt. IFB Customer service Person Visited & unable to find out the cause. As I have a small kid in my home, I requested them a written confirmation that there is no problem and the same will not be happening further else they should replace the oven. After several interaction and visit they confirmed for replacement and the Collected Bill copy. After that there was no response from their side. I called the customer care or their directed persons in Chennai at least 50 times in vein. They redirect each other. Sometimes directed person don't pick the call. Almost 6 months after the incident I still don't have any response from the company. The company it seems trying to cheat the customer by escaping and not addressing the issue.