An ad buyer who said she was fired by the Donald Trump campaign after trying to expose alleged “grift and greed” by top campaign officials and deep distrust at the operation’s highest levels has spoken out to the Daily Beast. The fired worker told the Beast under the condition of anonymity that she wrote an email after she was terminated that laid out her concerns that the campaign’s most senior leaders — Chris LaCivita and Susie Wiles — appeared to be directing millions of dollars toward companies that may be overcharging the former president. One of them, she said, is run by a major Kamala H…