Whirlpool - worst attitude towards customers

My microwave is not operational from the last 40-50 days. I have lodged three complaints with them with complaint numbers 13721,7412,9164. when initially diagnosed only fuse was not working. when there engineer visited he burned the whole microwave oven,now even if my machine is damaged by them they are not repairing them

1) Out of these complaints 13721,7412 were closed by the company with out informing me , with my signature and i was in the dilemma that my complaint is under process, when contacted customer care they told me that complaints are already closed which should be taken very seriously by govt consumer forms as companies are closing complaints without customer signature and with out informing them

2) Every time i am calling them they are saying that complaint is under process and will be taken seriously .

3) I dropped a mail to main office 10 days back but still no response from them. so even they don;t bother to reply

4) Even i try to contact customer care manger Mr , MANI and he assured me that the compliant will be resolved with in 24 hour, but no response I do know to whom should i approach, company is not replying for my mails.