MTS / Sistema Shyam TeleServices [SSTL] — Defective Data Card Replacement Refusal

Address:	Kolkata, West Bengal, 700039
Website:	selfcare.mtsindia.in

I have purchased one WI FI data card of MTS on 16-Aug-16.From 1-Aug-16, the device stopped function and on calling Customer Care, I was told that the device is manufactured by LAVA and I need to contact with LAVA only, and MTS cannot provide any support.I was told the same thing on visit to MTS Service Centre in my locality.
I have not purchased the the product from LAVA and was also not informed at the time of purchase that MTS would not take any responsibility in case of any defect.
I have emailed the same to customer care email id of both MTS and LAVA on 2-Aug-16, and none of them have replied.
I was also prepared to pay for a new data card, but the same was refused stating that MTS is merging with Reliance, so no new data cards are sold.
The customer care address of LAVA is also not located very nearby for me two travel down to submit one day and take back another day after repair.

The Data Card Details :
Model : DF800i
S/N : [protected]
MAC : FCDD550C4E16
MEID A1000039ABDC96
IMSI [protected]
MDN [protected]
Circle - Kolkata (West Bengal)
Date of Purchase - 16-Aug-16.