I'd give him another week to settle down before attempting to feed again. If he won't take live, say hello to your new pet rat! Jk. I'd say get a smaller rat than he'd usually take, they grow very quickly, and if you have to wait an additional week for the next feed attempt the rat may be too large. You can keep a small tub/spare tank if you have it with some bedding, a dish of water and whatever feed you can spare to house the rat. Or you can return it to the shop? Say your 'kids' didn't like it