Flipkart — Order cancelled without any information/reason

I have ordered an iPhone in big billion days sale on 2nd Oct. I made payment and order got confirmed and shipped. But after around 24 hour my order got cancelled without any notice or confirmation from my side. I tried to talk to customer care but they are not providing any solution. Now product is being sold at a higher price. I am forced to buy the same product at a higher price. This is completely unethical and a fraud. This seems like on the name of sale/offer fake hype is being created and they cancel the order if someone make use of that offer.