If I were the parent and you withheld my child I would go ballistic. I appreciate that a contract is a contract but this is their child. I am annoyed just typing this and thinking about it but if it actually happened and a provider wouldn't hand over my child, I do not want to imagine how I would handle that person. If they were lucky I'd report them but in all likelihood I would go ape shit and force my way in. Under no circumstances is it okay to withhold a child. If they are breaking the contract and your rules it is completely unacceptable, but then terminate but don't use their child in that way.