London, Sept 13 ANI: Enraged fans have slammed Madonna's performance at London's Wembley Arena, branding her sell-out show "disappointing". Angry audience were so miffed with the gig that they claimed that the legendary singer failed to get Into The Groove at the shaky performance.Fans accused the 50-year-old Queen of Pop of letting her fans down with a dodgy sound system, lip-synching and bum notes. Many people from the packed 74,000-seat venue claimed that they could not hear her vocals and there were others who left the show in between, insisting that one can easily tell when Madonna was singing live because there were so many wrong notes.It was when Madge started the Sticky and Sweet gig more than half an hour late that the crowd started getting annoyed. Many people, who paid 65 pounds each for tickets, had to miss their last trains back home because of the delay. However, it looked like 'The Material Girl's' star guests Gwyneth Paltrow, 35, Kate Hudson, 29, Penélope Cruz, 34, and Black Eyed Peas singer Fergie, 33, had a good time."We couldn't hear a thing. It sounded like the speakers had blown. When she was dancing you could see her lips weren't in time with the music, and when she was live I heard a few bum notes," The Daily Star quoted angry fan Natasha Jones, 32, from North London, as saying.Many fans even flooded her website, complaining about her failed to impress gig at Wembley.Leila from London wrote: "It was really disappointing - especially when the tickets were so expensive!" Meanwhile, a spokesman for Madonna refused to comment on the fans' complaints. ANI