I understand why people get agitated but the reality is that, in the level of the football atmosphere in which we now live, transfers are very complex. I've been lucky enough to be ITK on a few transfers, some of which I've shared on here, some I've had to wait a while before talking about and some, because of the source, I keep to myself.
Big ones can take months from setting up the deal to completion and all sorts of hazards lie in wait. For instance, our policy is that we will only pay the contracted agent and then only up to a certain level. If anyone crawls out the woodwork demanding money that we don't feel they're entitled to then they get told to do one. If that kills the deal (Isco definitely and, I believe, Hazard) then so be it. Van Persie would have been ours but either Mancini refused to sanction the sale of Balotelli to PSG or Mario refused to go. Players like Delph and De Rossi simply didn't want to move. Agents play games and so do clubs.
The point is that you can be as clever or on the ball as you like as a club or DoF but that's often not enough. It's a world populated by sharks and shysters and a lot is in the lap of the gods.