I had an AD that never returned a phone call, which was a real PITA. I solved the problem by just stopping in with my calendar in hand, sat down with him while he was on a lunch break and booked the entire year. I had to do that with this guy every year for 20 years. He was just totally irresponsible and wasn't going to change.

If this doesn't work, screw it - as DNJ said, there are lots of venues out there, more than any, one OMB performer can handle.

Good luck,

Gary