The 'Bad Romance' star's indecisiveness has annoyed organisers so much that they have taken away her prime-time 9pm performance slot and given it to Cheryl Cole instead, according to The Mirror.
A source told the newspaper: "The plan was for a London-themed backdrop with models of all the major monuments. GaGa would arrive on stage on a pimped-up green Rolls-Royce and sing 'Poker Face' and 'Telephone'.
"But the Rolls-Royce is now gathering dust backstage after she changed her mind and ditched the plans."
It is thought that GaGa later decided that she wanted a "sombre" performance to pay tribute to fashion designer Alexander McQueen following his death last week. However, she was then reportedly convinced by advisers that her idea could appear "crass".
The insider added: "So on Monday morning she changed everything yet again and promised to stump up the bill for the new stage, which is easily in the £100,000s.
"Now her show will be much more scaled down and Cheryl is taking her place in the running order."