Asaltantes a Caballo

This morning I achieved the Firemen's approval for the system I designed for a large farm. It has a 2,500 sq.m. stable for horses (it must be on of the largest of Israel) and a big hangar for machinery and feedstuff. Most engineers refuse to do such work because their signature - in case of fire and disaster - will draw them into expensive and long disputes with the insurance company, and the complicated calculations required for a well designed sprinkler system. I called the client to congratulate them and to ask for payment, and they said: "We love to pay, we are people who loves to pay their debts, but you are asking too much, we never agreed to such a sum". I sent a written demand to pay and asked them to check other water engineer's estimates. A signed and approved design is priced generally at 3 to 5 dollars per sq.m., so my fee of 800 dollar plus tax is ridiculously low. But they are unwilling to pay it. Once again, I was drawn into the work without ever signing a firmal contract: at first they asked to do a small thing and later the hangar and then appeared the stable, and I never stopped and demanded a written contract. Incredible how I am being screwed over and over by my "Clients".