Re-training litter habbits

My 3 are pooping everywhere. I was told to expect it when we moved but its coming up for 3 months now. Scooping up the poops and putting them in the tray doesn't seem effective. What can I do? Is there such a thing as too much space, should I restrict the space?

Also I need alternative litter suggestions, I currently use Megazorb as its cost effective and doesn't smell but its so small and bitty that it sticks to Ruby and ends up all over the house - the dyson is going to pack in, in protest! I dont want to use newspaper and hay as its stinks. Carefresh is too expensive at the rate I clean the trays and I cant get a hold of catobiolet the paper cat litter as that would be my preference. I've tried the wooden pellets but they're hard and I not too keen on them - anything else I could possibly use?

Tescos do a paper based cat litter which i have used. Easy to order online with the groceries too!! (yummy)

Ill have a look out for that, is it a Tesco own brand?

Its called paperlit. dont think its own brand.