This normally comes from improper use of the sprayer, or attempting to spray hurriedly when the nozzle has been turned to the OFF position.
When I worked with Bvlgari, we constantly had a stream of customers screw up the caps on our Black testers. I haven't handled one in several years so I'm going from memory here, but we found by removing the dial cap completely (turning it carefully, and pulling up sharply), we were then able to look at the underside of the cap/sprayer at the locking mechanism, and replace the cap properly again (I recall pressing down with the flat of my hand and my weight evenly distributed, until I heard a satisfying click) . Its important that you try and be as non-destructive with these parts as possible.
In the worst case scenario, where you might have removed the dial nozzle, and cannot get it back on again... have a hunt through your other scent bottles for a standard sprayer that will fit over the protruding hose sticking out of the top of the bottle. Often they will fit, and pump the juice effectively. Of course using the same sprayer on 2 bottles will contaminate the scents a little at first, so you have to be prepared to make some compromises.