After waiting for 2 days to see how the callback option works of 811 application, but unfortunately didn't receive any call so finally decided to call them, the operator confirmed about the transaction that I done on 26th September of ₹10001, and stated that the cash back will be credited on the 15th to the 20th of each month. I asked her about is there any specific catagory to be eligible for cashback to which she said every transaction done using DC is eligible for cashback there is no specific category. Let's wait one more week to see the real power of Super 811.