Some Trader Joe's coffee drinkers are angry they didn't get their caffeine fix, according to a new lawsuit filed against the retailer. 

Customers allege in a class-action lawsuit filed in California on Thursday that Trader Joe's deceptively advertised its French Roast Low Acid whole bean coffee, leading them to believe it contained more caffeine than it did.

Four plaintiffs who purchased the Trader Joe's coffee product, sold at the retailer's stores across the country, allege the grocer failed to disclose that the product contained less caffeine than typical coffee products. 

It is common practice, attorneys for the plaintiffs claim, to indicate a coffee product's caffeine content only when "some process is used to reduce the amount of caffeine contained therein."

"For example, full caffeinated coffee does not have any special labeling denoting that it is fully caffeinated, but 'decaf' and 'half-caff' coffees are labelled as such," the suit states. 

While testing shows that the French Roast Low Acid coffee contained half the caffeine of a regular blend, it was not labeled accordingly, the suit claims, leading consumers to "purchase the product believing that it is fully caffeinated when it is not."

Trader Joe's did not immediately respond to CBS News' request for comment on the lawsuit. 

Seeking damages

The suit claims that consumers rely on caffeine to fuel their work and personal lives. 

"It is so common that it is now cliché that coffee drinkers depend on the caffeine contained therein to provide them with the energy they need to get through the day. Accordingly, the amount of caffeine in a coffee blend affects a consumer's purchasing decision," the suit states.

A low-caffeine drink would not suffice for regular coffee drinkers, it adds. If they did choose to purchase a "half-caff" product, they would pay less for it, the lawsuit states.

Plaintiffs are seeking damages and for Trader Joe's to stop selling the product through misleading marketing, according to the lawsuit.