Mumbai -- Singer Sonu Nigam is disappointed after he had to pull out of a planned concert at London's O2 arena due to visa issues. The singer was slated to perform Sunday along with Pakistani singer Atif Alsam at Dhamaka Bollywood Concert London 2012, but cancelled the visit after his team members failed to get visas. Disappointed and enraged to inform everyone that I'm not coming to London. Hard to believe that except my visa, not a single visa for my group was done. Never happened in 20 years of overseas travel, Nigam said on Twitter. Don't know whom to blame. Our entire team's time and repute has been wasted. Only if the show is postponed now to another date, would we be vindicated. Prayers everyone, he added.