I don't know it this will be useful information, Bert. But when a company owed me $8,000 I called them and said I would be at their office in Orlando on such and such a date and time to pick up the money. This made an impression and they sent a courier up to pay me.
I understand your predicament. I recently called the CFO of a company and said "I'll get right to the point. I need money. When can I expect it?"
harpgirl