We completed a project in April 2022. We have been trying to collect retention for quite some time. They finally released 5% in December 2022. We have been trying to collect the final 5% and they keep having us rebill every month because "they were not able to process with the owner".
What does your contract say with regard to timing of payments? As a material supplier only, I am surprised that you agreed to have any retention withheld.