You surely know by now, thanks to jacket ads in major dailies and promotions on television, outdoors and the internet, that Flipkart is having a mega sale day. And competitor SnapDeal is snapping at their heels for Twitter trend dominance.

Flipkart‘s mega sale The Big Billion Day is essentially a pre-Diwali sale meant to capitalize on the holiday mood of this long weekend and as a doff of the hat to where the company’s billion-dollar journey began—founders Sachin Bansal and Binny Bansal (college-mates, not relatives) started the company out of a Bangalore flat numbered 6-10.

Flipkart founders sent personalized emails to customers informing them of the mega offers and even beefed up its logistics anticipating huge demand.

But the mega sale, which has been the focus of attention on social media all day, is turning out to be a PR disaster for the company, with many users pointing out, with screenshots and other evidence, three aspects that showed up the sales in poor light.

1) The discounts game deploys an old trick in the book—the company is marking up prices before offering what seems like a large discount.

2) The items shown on the homepage at huge discounts are actually out of stock. Too many error pages are showing up when trying to purchase discounted items, frustrating users.

3) Rival websites such as Amazon and Snapdeal are offering goods at cheaper prices than what Flipkart has labelled as the discounted price.

Twitter has been abuzz with people trying to buy items from the website and facing error pages—a problem acknowledged by Flipkart.

And even if you find that one product you want to buy, there is a big chance that it is already out of stock. In fact, some have complained about products being out of stock within just minutes after the sale commenced at 8:00 am.

Some users reported finding lower prices on rival websites despite the heavily marketed sales.

A post on MissionSharingKnowledge.com tracked how prices have been gradually going up in the run up to the sale, only to be slashed to the original price and presented as a discount on sale day.

A Flipkart spokesperson couldn’t offer an immediate comment saying “it is too nascent a stage to give any information.”

There are still a number of hours to go before the sale ends and Flipkart still might have surprises and flash sales in store that might help turn the tide of negative opinion.

And ultimately, the company will have gained huge learnings with its servers coping with record traffic and new users trying the website and the app. Flipkart typically doesn’t reveal sales figures so we might never get to know the revenues from this mega sale. But a spot of bad publicity might not be all that terrible given how many such sales must be ahead of them in India’s fierce e-commerce wars.

Update: In an statement on Monday evening, Flipkart said that it had “created history in Indian e-commerce.” “We got a billion hits on our site today and achieved our 24 hour sales target of $100 million in GMV (Gross Merchandise Value) in just 10 hours,” founders Sachin Bansal and Binny Bansal said. But there was little acknowledgement of the problems customers faced, except that Flipkart’s technology team had worked “towards addressing errors.”