What size tubs are they in? I've had success getting trouble eaters to start feeding again by dropping them into a smaller tub size for a couple of weeks.
Your temps and humidity sound right, the fact that they are all from the same breeder and not eating or showing any interest is a little weird.
If the breeder wasn't being honest its possible he had them eating African Soft Furred rats or mice and misrepresented their feeding history.