Samsung — Samsung Galaxy Note 4

I purchased new mobile on 8/7/2015 and after 2 days I open the box to use new mobile phone. Since then I am facing several problem like battery life performance, network, heating and battery periodically charge. I visited customer care and told them my problem and they said it's been 1 day late to replace as per policy. 7 days working days policy including weekends. Kindly help me.