Totally unreliable customer to work for -demand up front money

Extremely bad at paying accounts- I worked for them as a consultant for 3 weeks. 12 hours per day. He wanted me to stay longer, but had to return home due to ill health, possibly the hours etc. and the fact that I'm 73. I repaired machinery , repaired pluming, identified problems with mould and assisted in curing the problems, but bad design was the route cause. They would not address the issues fully due to cash flow problems. I identified problems with their premium lines, one of which involved candied fruit which were taking 4-5 weeks to make and had significant mould problems. I changed the process to reduce the time to 2 weeks and eliminated any mould. I wrote software to calculate the composition and costs of their main lines. It was not possible to write a full programme as their raw material costing system had too many flaws and had been set up with multiple standards, 1 kg or 1000 ml is the only acceptable way to handle all raw material costs, with the odd exception of eggs and vanilla beans. As soon as the cost per bottle, they buy bottles of 25 ml to 500ml for similar flavours and the system disintegrates. The yields of all recipes were require before I arrived. I found the very few had been done, and majority recorded were incorrect so all had to be followed through and verified. They changed their WiFi service provider whilst I was there and so had to use my phone and data (for continual internet searches etc)about a week and a half. I paid for my own accomodation and had to travel ~1000km to work and back . The total bill (including travel and accommodation, and spare parts material for repairs )should have to~R54,000, this was discounted to R38,000. This invoice was for September last year, to date she has yet to pay a cent on this bill. She has been using my qualifications to justify her factories adherence to GMP, whilst she will not implement any changes required.

Whoever the owner has had plenty of money to fund huge extreme parties and numerous overseas trips since September.