Amazon.com is hard at work promoting next week's Prime Day and the more than 100,000 deals available to subscribers. As with all things Amazon, it's intended to be a major party for consumers.

But longtime Amazon sellers like Jamie Whaley are in no mood to celebrate.

A licensed nurse, Whaley started a bedding business on Amazon that reached $700,000 in annual sales within three years. Her patented product called BedBand consists of a set of shock cords, clamps and locks designed to keep fitted bed sheets in place.

Whaley and her husband found quite an audience, selling up to 200 units a day for $13.99 a set. BedBand climbed into the top 200 selling products in the home and kitchen category. That was 2013.

By mid-2015, the business was in a tailspin. Revenue plummeted by half and Whaley was forced to lay off eight employees. Her sheet fastener had been copied by a legion of mostly Chinese knockoffs that undercut BedBand on price and jumped the seller ranks by obtaining scores of reviews that watchdog site Fakespot.com determined were inauthentic and "harmful for real consumers."

"Toe to toe we'll compete with anybody," said Whaley, who recently moved her family and a warehouse full of straps, clamps and cords from Texas to the mountains of Montana. "When you try to cheat or copy our products, it's a whole different story."

Whaley still counts on Amazon for 90 percent of her revenue but she's actively trying to drive traffic to her own website and partner with other retailers. She's lost all trust in Amazon.

Spend any time surveying Amazon sellers and Whaley's narrative will start sounding like the norm. In Amazon's quest to be the low-cost provider of everything on the planet, the website has morphed into the world's largest flea market — a chaotic, somewhat lawless, bazaar with unlimited inventory.

Always a problem, the counterfeiting issue has exploded this year, sellers say, following Amazon's effort to openly court Chinese manufacturers, weaving them intimately into the company's expansive logistics operation. Merchants are perpetually unsure of who or what may kill their sales on any given day and how much time they'll have to spend hunting down fakers.

Facebook and WhatsApp groups have formed for sellers to voice their complaints and strategize on potential fixes.

In May, CNBC.com reported on a Facebook group, now consisting of over 600 people, whose members have seen their designs for t-shirts, coffee mugs and iPhone cases show up on Amazon at a fraction of the price of the originals. The designers described it as a game of whack-a-mole, where fakes pop up more quickly than they're taken down.

It's not a topic you'll likely hear CEO Jeff Bezos discuss. Especially ahead of the second annual Prime Day on Tuesday, when Amazon Prime members get access to new deals about every five minutes. During the inaugural event last year, consumers bought 398 items per second, even as social media blew up with jokes about the quality of the offers.

While Amazon's focus has always been on consumers, the company is plenty aware of emerging seller angst.

In early June, at an invitation-only event for about 300 of the top marketplace merchants, the company's senior vice president of seller services Sebastian Gunningham was grilled by frustrated store owners, according to people with knowledge of the meeting.

During a fireside chat at Amazon's Seattle headquarters, Gunningham was asked repeatedly how the company was going to deal with the many ways that Chinese manufacturers were gaming the system, said the sources, who asked not to be named because attendees had to sign non-disclosure agreements.

An Amazon spokesperson declined to comment.

Outside merchants are a large and growing piece of the Amazon pie.

More than 40 percent of Amazon's unit sales now come through its third-party marketplace. Much of the expansion has occurred since Amazon started opening the floodgates to Chinese manufacturers, who previously had to count on middlemen, brands and private labels to reach global consumers.

Sales from Chinese-based sellers more than doubled in 2015 on Amazon's marketplaces, while the company's total revenue increased 20 percent. And recently, Amazon even registered with the Federal Maritime Commission to provide ocean freight, simplifying the process for Chinese companies to ship goods directly to Amazon fulfillment centers, cutting out costs and inefficiencies.

That's why you can get a box full of Chinese kitchen goods from a variety of sellers delivered in two days from a warehouse in Kentucky.

Critics say Amazon hasn't put the necessary checks in place to manage the influx of counterfeits.

To unsuspecting consumers, fake products can appear legitimate because of the Fulfillment by Amazon program, which lets manufacturers send their goods to Amazon's fulfillment centers and hand over a bigger commission, gaining the stamp of approval that comes with an FBA tag.

Furthermore, Amazon's commingled inventory option bundles together products from different sellers, meaning that a counterfeit jacket could be sent to an Amazon facility by one merchant and actually sold by another.

"Amazon is making money hand over fist from counterfeiters, and they've done about as little as possible for as long as possible to address the issue," said Chris Johnson, an attorney at Johnson & Pham LLP, which focuses on intellectual property and brand enforcement and represents clients including Forever 21, Adobe and OtterBox. "Word is out in the counterfeit community that it's open season on Amazon."

It's not just niche brands like BedBand feeling the pain.

Birkenstock has seen dozens of stores at a time hawking its Arizona Sandal for $79.99, a full $20 below the retail price. The names of the online storefronts change all the time, one day including the monikers Silver Peak Wine Cellar and Ryan Hollifield and the next Keila*Knightley and Bking sewneg.