Just because they hadn't gotten it doesn't mean they knew that Trump was holding it up. It wouldn't be out of the ordinary for a payment like that to be delayed. In fact, was there even a due date on it?
And, by the way, I can totally see something like this happening in a business context. Even if a payment is due a day before a call between two companies, I can see the paying company holding a payment until after a call, to see how things go. It's only a smart move. One could argue that it would have been stupid for him not to hold that up for the call. If he paid it out, then had a call where he wanted him to do things, that would be like Obama: Give up things, and then hope they do what you want. It is better to hold things back until people do what you want.