I think you are underestimating how quickly chickens' health can decline. A healthy looking chicken can go from normal to dead in 24 hours. You already know the feed has caused serious problems for one of your birds. Your first priority should be rectifying that asap. Not later when you get the...
I don't think anyone is expecting you to feed moldy food to your chickens. But rather, why you haven't returned that bag of bad food and gotten new food yet, after almost 2 weeks?