Sony India — Replacing my speakers for my led tv given defective peace of speaker for my led. speaker

Address:

Ghatkopar, Room 15 Asalpha Village Ghatkopar West

I have been approched for sony service centre
For replacing my speaker for my led.
The service department person came and he has replaced my speaker for my led tv.
But after speaker was getting rough voice for my led and it wae worst voice for my led.
And i am being follow up with the guy but he is not responding his name amit soni and his boss name wae arun. This both guys are not recd my phone no reply of message.
And also i paid for the sevices they both have given. Than also they are not responding.
In this scenario what should i do whom to complain no one there to help me.
I am calling customer care but they are telling your no is not registered.
Pls take this case oh high priority.