CR is right.
The only other thing that seems to achieve more than Good Faith Bargaining is court cases. The Flight attendant union seems to get their wins thru court action. Maybe a string of multiple cases like RP/ Housing/ Statutory Holiday Pay/ By Pass Pay/ Lack of response to ASRF's/ Duty of Care to provide transport/Accommodation in home base after WOCL trips that not only see you at the limit of fatigue for aviation but also poses a known risk to you and others on the road for the drive home.
Just some ideas on where to go next???