notify them that if they don't pay you in full, that in 24 hours you will be forced to use Dunn & Brad Street to do debt collection..

the risk of being pursued by one of the biggest debt collection companies in the world that also results in a bad credit risk will scare the shit out of them and they will pay immediately..

if you can afford it, I'd just issue the invoice for collection with Dunn & Brad Street just for good riddance as I hate companies who screw people over payment..

lists ALL the company directors as named entities along with the company as "creditors"..