I recall the aircraft was Halls Creek for Broome. Check out the ERSA entry regarding buying Jet A1 at Halls Creek- PPR for carnet cards, otherwise cash cheque or credit card. Maybe the company is too cheap to think about the PPR and buying the hideously expensive fuel, and the PIC wasn’t too keen using his/her personal CC?? Speculation here, but it’s certainly possible given how other operators in that region conduct themselves......