Motorola — Service issue

Address:

Ernakulam, Kerala

Sir,
I have purchased my Moto G on 28/04.2014. 2 weeks back it keeps on hanging and later it shows a black screen and an android logo saying erasing on black screen. I took it to the authorized service centre (ADR Technologies, Kochi, Ernakulam) for repairing it. They have given the recipt and asked me to call back after a week. When i called them, they said it can be serviced through out of warranty because its been already serviced by someone else. Also said i have signed the receipt under out of warranty. When i checked my receipt, warranty status column was empty. but there is one more coloumn, "component replaced" there they written that its out of warranty. Now they saying that its Mother board is dead and it needs to be replaced, and cost is 5600.
I have the basic common sense of not servicing a warranty product in unauthorized service centre, that too an exclusive online product.

I strongly feel like the service centre is trying to get money from me by saying its out of warranty.
I want this to be serviced under warranty.