BSNL penta tab is703c — got non functional speaker

Address:

Patna, Bihar

i ordered a bsnl penta tab is703c from naaptol.com online.
i got a defective piece which speaker was not working.
i complained in naaptol,penta company.just withn 5 min of recieving the tab.but they just blamed each other and did nothing.
then i sent it t customer care of penta ,they took 28 days to repair it but returned the same defective piece its speaker is not working now also.
and i cant send it to the customer care again and again for months.