I worked (drafting) on multiple projects for a Florida tile contractor with a standard practice of holding a retainage on all projects. I finished work in 3/28, Invoiced on 4/15 but my invoice wasn't denied in writing until 8/31. I was basically strung on through other projects with "we'll get that payment next month". Large Contractor, Major Hotel Chain. Does the retainage system allow me to use the 8/31 date when I was told in writing my invoice was denied and allow me to file a lien?