Singer Katy Perry is known in part for her ever-evolving hairstyles, but that wasn't enough to extend her contact with the British hair care company ghd, which dropped the pop star as its spokesperson.

The reason? According to ghd, she's just not as popular as she used to be.

Ouch. That must burn like the worst curling iron mishap.

Now there's a $2 million lawsuit in the works in response to the whole thing, with Perry's agent saying she's owed more cash out of the initial $4.5 million, two-year deal made back in 2011.

Katy's people say she's due more dosh according to an oral agreement to extend her contract, while a representative for ghd (which stands for Good Hair Day, by the way) says there was never any such agreement and Perry is being dropped because "market research shows Europeans just aren't that into her anymore."

With Perry's agent threatening to sue, ghd's parent company Jemelia Group struck first -- it filed documents asking the courts to block the blue-haired singer's team from suing.

"Jemella's attempt to embarrass Ms. Perry by including defamatory statements about her in a public filing is shameful," Katy's rep told TMZ. And Katy herself said, "They're backing out of the deal because of an ownership change, and just throwing shade to hide their bad faith."