LG Google Nexus — Product failure while on charging

Address:

New Delhi, Delhi, 110085

I put my nexus 5 on charging at 16 % when i went to sleep at night.
in the morning when i checked phone was swithced off and dead permananetly.

service centre says motherboard failure due to update .
why should i pay for company's mistake. how should i repair it.
[protected]
chetan