Britney Spears
Judge Britney Spears poses at the party for the television series ''The X Factor'' finalists in Los Angeles, California November 5, 2012. REUTERS/MARIO ANZUONI

Britney Spears has first kicked off her two-year "Piece Of Me" show at Planet Hollywood in Las Vegas on Dec. 27 last year. But a recent report came up citing Spears had put Las Vegas and everything it stood for to shame.

Instead of delivering flamboyant and entertaining shows, concertgoers agreed they felt shortchanged for paying so much for lousy and boring performances. Radar Online exclusively gathered feedback on Spears' "Pieces of Me" performances at Planet Hollywood and reported that majority of the concertgoers were disappointed, sad and angry.

According to one concertgoer, "After watching the lethargic dancing along with the terrible miming....we decided to leave the venue."

The concertgoer added she cannot believe the tickets were selling for up to $525. The show was shockingly fake and Britney looked bored as hell, to put it bluntly.

Another concertgoer also complained about Spears' apparent lip-sync. "At the show, Britney Spears was blatantly lip-syncing along to a track," the disappointed fan said. "Anyone with ears could tell!"

Complaints of Spears not singing live were not new. Even though she promised her fans that she would sing live, the pop star had been caught lip synching two times back in February, Radar Online reported.

There was a time her vocals continued despiteher mic flew off her waistband and there was also one time when Spears' voice can be heard rocking the whole arena even though her lips were not moving.

"There have been so many complaints over Britney's lip syncing, action had to be taken," a Planet Hollywood insider shared RadarOnline.com.

"Now, her microphone is switched on throughout certain songs."

According to Radar Online, Spears may be oblivious to all the negative feedback on her performance. The mother of two is always shielded by her manager, Larry Rudolph, from negativitiy. Larry even kept the bad reviews on her album, Britney Jean away from the sensitive heart of the pop star.

"Britney doesn't even have access to the internet and lives in a bubble," an insider said at the time.

"No one wants to upset Britney. If she were to read anything negative, it could send her into a tailspin!"

Maybe this is the reason Spears decided to add new performance dates to her tour, Huffington Post reported.