The London Sky Bar in London's Millbank has been rapped over the knuckles by the Advertising Standards Authority (ASA) over the promotion of its 2013 New Year's Eve party.
The single complainant, who attended the party with 1,300 other guests, listed nine areas where the online advertisement was misleading.
These included the fact that the complainant was only given one cocktail, whereas the ad described a welcome cocktail reception "serving guests exclusive cocktails from our world-class mixologists".
Other wording deemed misleading included the phrase: "Welcome in the new year with the resonating chimes of Big Ben just in front of you" because the landmark clock was not used as a feature in the celebrations.
The ASA upheld all nine issues and ruled the claims must not appear again in their current form.
A spokesman at Altitude London, which operates the London Sky Bar, said De Vere Venues were the contracted management company for the event. It added that De Vere had been relieved of its duties on 3 January 2014.
"Prior to the De Vere Venues organised event, Altitude London had hosted successful and well received new year events for seven years. Since De Vere Venues' departure, 2014 has seen Altitude London expand its reputation for high-quality events, with the launch of three restaurants alongside a new specialist business venue and a strong portfolio of digital features," said the spokesman.
"Altitude London intends to run a New Year's Eve event in 2014 to standards enjoyed by thousands of international and local guests for many years prior to 2013. In doing so, Altitude also intends to advertise their 2014 New Year's Eve event appropriately and welcomes ASA clarity on the subject."