Oki slight delema...I got this cat that for some reason dont wanna piss in his box

hi pisses on the floor

so i bought him these crystal ball thingies and he pisses in them the odd time but still mostly on the floor
I would get rid of him but i just got him from the Humain Socity..so that to me would be wrong just to return him there cause i got 2 other cats from there also...
So any one know how i can fix this cat piss problem???