Joe Kool's of Troy LLC ,Joe Kool's Restaurant Complete a major remodeling project and not pay us and the trades Troy Michigan

We completed a $1,000,000 remodeling project at cost plus and finished in late October.  They are now open and have not paid us the balance of $410,000 owed to us.  We have completed the punch list, got them a C of O, their architect has reviewed and signed off for the final payment.
 
They are looking for a reason, which there is none, to not pay us or pay a lot less.  We have been offered to take $150,000 less to settle and for now reason.  The job turned out great, they have no complaints.  They just want something for nothing.  We have filed a lien on the project, however, it will take a long time and extensive costs to go after the money.  This is not fair to us and the eighteen other trades (small companies) that are owed money.   It’s like premeditated lacency and we need help, all of us need to get paid.