Boult Audio — No response after I sent the product for service

Address:

No.5, Rathinam City, Opp to Old bus stand, Chengam, Tiruvannamalai

I have sent a product for service.there is no response for multiple mails and multiple calls. Always they are saying they will check. But it's almost 15 days they are not responding.i have couriered the product to their delivery address which they asked me to send. I have sent the product on 27tb March. And it was delivered on 31st March. Will attach the mail sent to them and courier slip