Leaders of a black economic boycott protesting the snubbing of anti-apartheid leader Nelson Mandela during a south Florida visit last summer still want an apology. The group hand-delivered Friday to each of the mayors and commissioners of Miami, Miami Beach and Dade County a written request for keys to the city and official welcome proclamations for Mandela. Leaders of the city's black community urged convention organizers to boycott Dade after local officials failed to welcome Mandela and his wife, Winnie, during their visit to Miami June 28. The controversy began when he refused to repudiate ties to Cuban President Fidel Castro, Palestine Liberation Organization leader Yasser Arafat and Libyan strongman Moammar Gadhafi.