The British beauty ' who is reported to have been replaced by Nicole Scherzinger on the judging panel of the show alongside L.A. Reid, Paula Abdul and Simon Cowell ' did not expect to be sacked and is upset Simon, with who she worked on the UK version of the show, did not tell her of the move in person.
A friend of Cheryl's said: "She is completed shocked and stunned. She never saw this coming.
"The fact Simon didn't tell her in person hurt. She never thought he would do that to her."
The 27-year-old singer has told friends she feels like she has been strung up by her former boss and was not given a chance to hold her own on the musical TV talent show.
She is quoted by the Daily Mirror newspaper as telling a friend: "I've been hung out to dry and I know who's to blame. I've had no opportunity whatsoever to prove myself and instead they've just cast me aside like a fool."
Now Simon has been accused of "losing his touch" on the show, with Fox forcing his hand to release Cheryl, proving he is no longer the "arch manipulator" he thinks of himself as.
A source said: "Simon Cowell wants to be seen as the arch manipulator, the controller of everyone's destiny, yet he seems to be losing his touch.
"He thinks he keeps everyone on their toes by leaving announcements until the last minute, but it just looks desperate. He prides himself on being able to charm everyone into doing hat he wants but the tactic is not working.
"He couldn't get most of the US stars he wanted for 'The X Factor' and the Fox guys over-ruled him on Cheryl, which has got to hurt."
It is now thought Cheryl will return to the UK version of the show, alongside Gary Barlow, Kelly Rowland and Louis Walsh.
A source told The Sun newspaper: "She is hurt but has agreed to come back. She doesn't want her British fans to think she would desert them. She is determined to make it clear she hasn't failed."