Hey OP, I'm sorry you're going through this with lack of support. I was worried they wouldn't agree to take the puppy back. They are under no obligation to do so and they know it. If it is shown that the puppy had congenital problems, or issues arose through neglect, they still don't have to take the puppy back unless this is found to be the case in court. So, you may have to accept a financial loss here.
Lesson learned: breeders who don't breed ethically will not treat humans with compassion or ethics, either. Ethical breeders have a lifelong clause, usually in writing, that they will take their puppies back for life, for whatever reason. Ethical breeders also send you home with at least a weeks worth of free insurance usually arranged via PetPlan or the Kennel Club.
Anyway, what's done is done and we are where we are.
Don't lose heart!
He may be scared of metal if it makes noise when he drinks/eats from it. A ceramic bowl is a great idea!
My little puppy got spooked from metal and is still strange with it if he thinks it will clank on tile. So, yes, try a paper plate or ceramic. Great idea.
Chicken may be more enticing for him but, if he does go for it, try to keep him on the same food for a week before trying to go back to kibble or whatever you intend on feeding him because you don't want to switch foods, too often and too quick, and give him an upset tummy. But, chicken is a great, short term solution so definitely try it. Make sure it's cooked because the smell is enticing.
How else can we help?