Have you tried putting their favorite treats into their new food and water bowls (with water and food in them as well)? That might get them to gain the courage to give the new bowls a try. You can also try sprinkling some treats around the bowls as well to get them closer to the bowls if they are still wary. Then toss treats right into the bowls and they should go after them. Once they figure out the bowls are not going to eat them, it should be ok. ;)
What happens when you put them on the ground? Will they use them? If it's a nippled watering system I understand that defeats the purpose. How stable are the containers?
And lastly, is there any storage or shipping film (light grease or otherwise) that's covering them, or any noticeable odor? Just spit balling here...
How strange that a duck or ducks can be so picky!! It seems to me that there is something about the containers that are causing them to not trust / freak out about your new waterers / feeders. Color? or any other graphic on it that might be offensive to a duck?? Now I'm really reaching. What about the old "tough love" trick? Put their food out and not feed anything else until they eat out of it. There are limits of course, but those are best set by you. I'm clearly stumped.
Well, now that you said that. BAM! Are they getting their fill through foraging maybe? I know for us, our feed usage went up in the winter but now that warmer weather is coming on, the feed bowl doesn't get quite as empty as it did a few weeks ago. They might be filling up foraging. I think a natural diet is better for them, so no, I would not stop allowing them to forage. Do you have an old bowl laying around you can throw food into and see if they eat it? Ours forage and hit the feed bins all day long. I stopped putting feed and water in their night-time coop last year and that helps significantly with keeping their sleeping quarters clean.