Has it always been like that, or what has happened/changed to cause the problem (like an accident)?
One thing you could try, there are a number of rubber mounts that support the boot lid when its closed. Try adjusting them lower by turning them clockwise. Just turn them, say half a turn or so until the boot closes. Don't over do it - the boot needs to be under some tension otherwise it won't "pop open" when required.
Something may have bent or moved the chassis hook. It can be adjusted by loosening the bolts or bending it.
At a guess, I reckon loading/unloading heavy things from the boot has bent or moved it a couple of mm.
There is an internal spring that breaks and if you drop the replacement one while it in the unlock position the bloody spring will come off.. have to cut them open to replace spring.. Buy a replacement lock assy