NYDA do not pay their accounts!!!!! Empty promises

Once again a government agency which doesn't pay accounts! When we were contracted to do the necessary repairs and upgrades we stipulated that we want a 50% deposit and the rest must be paid upon completion of the job. Because of previous dealings with NYDA when we had to wait about 4 months for payment from them, we informed them that they do not have any credit facility with us. They paid the deposit and we completed the job in January already. Currently it it 23 February 2016 with promises of payment and you can guess it up to now we have not received any cent further. First couple of weeks my emails and calls was just ignored. After several attempts and a threatening letter one manager responded and indicated a pay date of 18 February - which did not happen. Trying to contact him again, he is on leave. So please be aware before you do decide to deal with NYDA, you must be willing to wait an unlimited time for your money to be paid. Please note as well up to now they have not paid one cent towards the interest which was charged for late payments. Maybe because they are government they are allowed to get away with it because they are above the law.