NHBRC is not a worthwhile organisation

We are trying to address a builder that has ****** over half a million from us and is registered with NHBRC.We have laid ******** charges.We are also paying large amounts in remedial work for bad workmanship aside from the theft losses. His company is Prosperitty Builders ( yes two t's)He has 3 judgements against him. NHBRC is not helping us to deregister him. We have called and sent several emails. They are useless in helping and it seems as if it is just a convenience and not an organisation that has credibility in controlling their members.