If you are sure about the item that you are purchasing at Infibeam, with partial cash and rewards, kindly follow below steps.
Step 1: Find out the worth of your reward points. It seems you have already calculated it to be Rs. 1000/-
Step 2: Calculate the remaining amount you will need to pay. In your case Rs. 400/-
Step 3: Create your Infibeam account.
Step 4: Recharge your Infibeam Wallet account with Rs. 400/- with your debit account or credit card. Link provided.
Step 5: Add the item you want to buy to your Basket (shopping cart) and select "Check out"
Step 6: As part of payment options, choose to pay from your Infibeam Wallet account. So, Infibeam will deduct Rs 400/- from your wallet.
Setp 7: The payment page will ask you to choose the payment options for the remaining amount. Choose your Credit Card Reward Points option. You will be able to pay the rest (Rs 1000/- from your reward points)
Step 8: Cross your fingers and wait for the delivery :) Enjoy shopping.