I am a material supplier, who supplied a $3k fire valve to a fire contractor on 12/5/17. That contractor installed it in an apartment complex in Mesquite Texas. The contractor had received the invoice on 12/5/17 as well as a statement every month on the 1st and 15th since. I was getting pushed off, but now I need to follow legal action. What steps do I need to take to start this process thru ZLien? Also, is there a point in the process where I can physically go and repossess my product?