[Emroy]

I'd be careful with some of the "creative approaches", as there are strict guidelines on exactly how outstanding invoices can be followed up.

I believe in fostering long term relationships with clients and giving them opportunities to make things right (Which by the sounds of things you have done) But I guess, as much as it hurts, sometimes we just need to accept the reality that some people don't pay invoices and experts need to be called in to assist.