Flipkart will return your money in a Day

If your bank and account supports IMPS transfer, then Flipkart one-day refund policy will apply to you.

I am not sure how it works for credit card payments and EMI payments.

An official statement from Flipkart as below.

“This is a huge step in the payments front and has a big impact in the way customers shop on Flipkart.  An instant, hassle-free refund experience, combined with consistent and accurate communication to the customer is definitely going to be a breakthrough, and a way forward for all future payment innovations,” said Punit Soni,  Chief Product Officer- Flipkart

As per PTI..Continuing the innovation journey by announcing this newly launched payment mechanism, Flipkart aims to ensure that refunds for Cash on Deliver (CoD) orders are credited back to customers instantly, as soon as the product reaches the Flipkart hub," Flipkart said in a statement.