Except, you're very likely not going to get the money, so I hope the "don't have the wherewithal to give the company this free loan" is an exaggeration. You should cut your losses. This is a sunk cost for you. Use your creativity to work on furthering your ambitions and career from here. Live for the future, not the past.

Make it their fear - they are still in business, so somebody is getting paid.

Call them up and tell them straight out that they have a week to get the money otherwise you go after them in court, which will throw the company into banckruptcy.