The developer received the permit from my drawings, and the single family residence is under construction. He is a year and a half late on satisfying an invoice for changes to the design. He paid half of the invoice, and still needs to pay the other half. I did not agree to him paying half the invoice, and he has been saying he will pay me. I am a registered architect in the state of Florida. I am out of ideas on what I have at my disposal to remedy this situation. Thank you Mark