Zoe Alexander from Caerphilly, South Wales, claimed she had been forced to sing a Pink song on the show last year and that X Factor staff had dictated her outfit and hairstyle for her audition.
She also said her performance was sabotaged, that footage of her was unfairly edited, that judges' comments were "doctored" so that their more sneering remarks were omitted, and that she was unfairly portrayed as a "mixed up idiot and laughing stock" when she went on stage.
However Ofcom have rejected Zoe's complaints, saying in their view "the programme showed a slightly edited, but accurate, version of what happened."
Zoe was stopped by judges as she sang the Pink track 'So What' after saying that she wanted to find her own identity. She was asked to sing another song, not by Pink, but her rendition of an Emeli Sande track failed to get her through.
After her rejection, she told judges: "You told me to sing a Pink song, I didn't want to sing a Pink song. You guys told me to sing a Pink song."
The judges - Gary Barlow, Tulisa Contostavlos, Louis Walsh and Nicole Scherzinger - denied telling her what to sing and Zoe was then seen throwing her microphone as she left the stage.
ITV said that untransmitted footage showed her physically attacking a cameraman, and alleged that she slapped the series producer in the face after they stopped filming.
Ofcom found that programme makers had not been unfair, saying that although "it appeared to Ofcom that Miss Alexander had preferred not to perform as Pink, but had been advised strongly by the programme researcher to include a Pink song in her choices", she was given an opportunity to sing a second song in her audition.
The regulator said that footage of her was not unfairly edited, and that she was not unfairly portrayed in the show.
It "did not consider that she was portrayed as a 'laughing stock', but rather as someone who was working as a tribute artist, but aspired to making a success of performing in her own right," Ofcom added.