Boat — boat - not responding to replacement request after picking up item

I had purchased boat rockerz 255 last october. I was experiencing low sound issue and as it was under warranty so i registered the complaint on 21-may 2020.
It was picked up on 28th or 29-may-2020.
That was the last time i heard from them. I have written several emails to them but didn't get any reply from their side.
I again wrote to their given email ids a week before, again to my dismay got no reply.
I was patient coz of the on-going lockdown situation, but it's literally been more than 3 months! And i haven't even got any response from their side. Nor have they updated anything on the status tracker. (Ticket number 1112783.)

That's just wasn't expected. Very bad and unresponsive customer care service.