I learned very quickly to set standards and stick to them. One quilt for hire, at first glace, seemed poorly made. I asked the lady to help measure it with me. Found out it was her first quilt. As we stretched out the top, we started seeing holes. "These will need to be corrected before I can quilt this." Did more talking about quilting and how to fix things. Asked her to fix it and bring it back, I'd then quilt it. She seemed very pleased to have received constructive critique but never returned.
Set your standards. Have them printed and provided to the coordinator. Don't feel quilty when someone else presents unacceptable products. If you let someone else keep pushing your standards, they'll just keep testing you-just like kids.
If binding isn't provided, return with "no binding provided". If the back isn't large enough, return with "back is too small". If construction is unacceptable, return with "seam allowance inapropriate, etc....".
I make lots of donation quilts and I'm known for they're quality and design. And I pick out the ones I'm willing to quilt. I refuse to do binding for someone else's quilt. There have been times I've trimmed the front to fit the back. There have been a few quilts, I've reconstructed due to quality or workmanship or design-I knew it was needed before I accepted the project. Sometimes I get tired of the quilting and want a challenge.
It's all volunteer. I define what I'm willing to volunteer.