Tiffany and Co. have filed a lawsuit against Costco for their sale of diamond engagement rings which were labeled “Tiffany”, but which the company claims were not produced by them.

A Costco customer tipped off Tiffany to the sales and they immediately launched an investigation, saying that Costco has been selling these rings for years and using signage marked “Tiffany” when in fact they aren’t associated with the high-end jeweler at all.

“We now know that there are at least hundreds if not thousands of Costco members who think they bought a Tiffany engagement ring at Costco, which they didn’t,” Jeffrey Mitchell, an attorney for Tiffany’s, said. “Costco knew what it was doing when it used the Tiffany trademark to sell rings that had nothing to do with Tiffany. This is not the kind of behavior people expect from a company like Costco, and this case will shed a much needed light on this outrageous behavior.”

The lawsuit alleges trademark infringement, counterfeiting, unfair competition, injury to business reputation, false advertising and deceptive business practices against Costco and reportedly asks for the forfeit of all ring sales, plus damages of $2 million per infringement. The suit could prove to be a pricey one for Costco; the company hasn’t issued a statement on the matter yet.