They weren’t laughing. Chris Russo and Mike Francesa took some shots Wednesday over WFAN’s struggling ratings in the months after Francesa’s departure, and morning show hosts Boomer Esiason and Gregg Giannotti, as well as WFAN’s vice president of programming, Mark Chernoff, responded Monday morning. “Classless, it really was,” Esiason said in comments first noted by Newsday.