Ash - the handbrake cable for the drivers side wheel used to run near something hot and mine melted, the cable was rerouted and should be done FOC - ask your dealer or factory...
Maybe you're making the mistake of parking on a hill, the handbrake will not work if that is the case. Try to park on a flat level surface and you should be OK.
Seriously, IME the handbrake is ineffective on steep inclines.
After that, I noticed houses and immovable objects overtaking me, whilst stationary at traffic lights, with the sharp end of the car pointing upwards on a slight incline.