In general, a man withholding a Get is wrong and is hurting himself too. Who would want to marry such a person?
I do know of a case where the wife’s lawyer advised her to claim the husband molested his children, so she gets full custody. The man lost his job status over it, yet the claim was false.
He withheld the Get insisting the wife recants the false statement, so he can get his life back. This situation, it seems to me, is one of the few situations where not giving the Get has some merit.