If a person has their property in a trust, can a lien be placed? How do we know if the property is actually in a trust?

We are a restoration company that provided emergency mitigation services for a customer. Their insurance denied their claim and now they do not want to pay for the services. We told them we would place a lien on the property and they stated we could not since the property was in a trust. We want to know what we can do going forward to collect our funds