If I'm reading you right, you didn't speak to him, you spoke to someone at the office and who knows where the ball might have been dropped. I say call again and ask what's up. Will someone be able to do it within the time frame or should you go ahead and find someone else this year? As Amara said, just approach it as if it's any other business transaction. Even if he's uncomfortable about his ex, he can save face and say he's too busy, but my money is on the message not getting to him or to one of the lads.