Open up the controller and they'll probably be dial/screw of some sort that you can turn to adjust the pressure setting
In fact scrap that, just looked at the photo on the link you've posted.
The right k nob is the pressure/calibration setting, it needs adjusting
I would have thought you need to turn it up a bit if your pressure switch is dead ending (i should point out that the pumps pressure switch shouldn't be wired in, i dont think, if you're using that controller)
Also check for kinks in hose etc...
Edit - i think its one of ian sheppards controllers, he'll be along soon