Flipkart — Selling Redmi 1s mobile when out of stock

Address:

Gurgaon, Haryana

I ordered Redmi 1s on flipkart flash sale on 2nd september and they were showing 40, 000 units for selling. I got one in my cart and ordered it but now they are telling they are out of stock and will ship once they get stock this tuesday. My concern is how can they sale mobile if they dont have in stock. I bought my mobile from those 40, 000 units, so its very simple that i got it on the first time. Please check this because they are making fool of customers.