They prefer damp, heavy soil, and bright light, but not too sure how well they cope with your high temperatures and very hot sun. It's possible the plants were too stressed already when you bought them, and may not be recoverable. Move the suffering one into the shade and keep thoroughly watered in hopes it may recover.

Will do as you suggest, and Thank you so much for the advice. I should have taken them back really as they were extremely rootbound and I knew they werent right. Fingers xxxxxd