spray bottles are great but not perfect. one of my cats hates it but if she wants attention she knows she'll have to endure the bottle. kinda like kids who will accept negative attention over not enough.
a better idea is to give the cat an
alternative like a cat tree house type of thing. my cats love the them. just like a cat who scratches your chair a scratch pad usually fixes the problem. instinctively they are climbing animals and the desire for the high ground is natural.
the mistake in training cat or dog is to engage in a battle of wills and sheer force; you'll raise a 'psycho" cat if you do. don't be cruel and remember if the anxiety of the animal is piqued you'll just have a miserable cat... and human.
for those who don't 'like' animals... i truly pity you.
edit: remember that your cat is still young. always maintain patience and in time this will work out.
and by that i mean either you or the cat will learn who's boss.