Flipkart — damage of a product which i bought 40 days before

Address:

Hooghly, West Bengal

I bought MOTO X 16gb from Flipkart on Big Billion day sale on October 6 and they deliverd on October 11..As the product delivered in time i was busy with my excitment towards the phone..soon after somedays i realised the back cover is damaged a little but i neglected it because its a very little break..but after one month the battery keep dying and finally it is not charging at all.And the back side the phone get softend which i dont know what to do..The Flipkart says it can take returns for 1 month period but it is only 10 days late and the phone costs 18000 rupees..Please accept the return