Amazon India — they took order, took money and later they are not delivering product saying it has been cancelled

Address:	New Delhi, Delhi, 110047
Website:	amazon.in

I purchase product (
Wd my passport 3tb portable external hard) here at deal price 2, 999 on 12 sept 2017, now order is confirmed and i paid money for it, after 1 day amazon say this is technical issue by their side and your order has been cancelled and now you have to buy for new price at around 10, 000rs which is much greater than rs. 2, 999.
They offer deal price and later cancel it, and when i talked with their customer care they behave very badly adn saying it is technical fault we can not do anything, now you have to buy it at new cost. Why they cheat customer taking money name of deal and later cancel it.
Order id #[protected]