Atomic Kitten only reached number 77 with their comeback single 'Anyone Who Had A Heart' earlier this year and Katona insists they were wrong to not invite her back for the reformation.
She told New! magazine: "I made that frigging band, but they never bothered to invite me back.
"I know their single bombed but that’s because without me they’re nothing."
Katona left the girl group in 2001 and was replaced by Jenny Frost.
> Click here for our review of the single