50% of your money back seems like a sham. If the pet shop did give you a faulty lizard. I would follow with chuck norris round houses for everyone in the shop until I got a full refund. I don't have much exp with monitors but I have a 36x24x18 cage atm with a 150Watt mega ray and the cool side is hard to keep under 80 as well. I don't really worry about it though because my monitor has dug a foot hole down in the soil and it is plenty of coolness down there. Prolly around 70 degree, you must mist a lot.