HDFC Bank — interest on no cost emi

Address: Branch 542, Trade World, A Wing, Ground Floor, Senapati Bapat Marg, Lower Parel Mumbai Mumbai City District Maharashtra India - 400013

I have purchased a laptop on no cost emi from flipkart using hdfc bank credit card.in my current credit card statement, it's showing mer emi, int and it's a huge interest amount. While i have purchased the product on no cost emi, why this interest amount.