Flipkart — Item returned before 3 weeks but not received refund

Address:	New Delhi, Delhi, 110094
Website:	Www.flipkart.com

Regarding the refund od[protected] [incident: in[protected]]

I have order dubaria ink cartridge but they have sent defective product. I have raised for return and they said to me that you have to send item to us by courier after receive the item we will initiate your refund. I have sent the item and the item was successfully delivered to there office on 5th august 2016. Then i sent an mail that item was successfully delivered and i have sent screen shot of delivery status then they revert me that we will confirm from our seller then we will initiate your refund in 48 working days
Today is 24 august but they are not reverting any mail, they don't initiating my refund, and they are saying that we haven't received any item infect i have already share the delivery status screen shot.
Kindly submit my complaint against flipkart
Screen shot of mail attached here with

Regards
Rakesh kumar